Sim City 4 Devotion Forums

SimCity 4 Devotion Custom Content Showcase => Network Addon Mod (NAM) => Topic started by: z on August 02, 2008, 07:07:50 PM

Title: NAM Unified Traffic Simulator Development and Theory
Post by: z on August 02, 2008, 07:07:50 PM
I am starting this thread to describe a new traffic simulator I have built.  I will be explaining why I built it, what its major features are, implementation details and rationale, and plans for testing and feedback.  I will decide what to do next depending on the feedback I receive.

Before anything else, I would like to thank all of those who have gone before me and helped bring SC4 traffic simulation to its current state.  I would especially like to thank jplumbley and mott, who not only created our current state-of-the-art simulators, but who also have been such a great help to the whole community by taking the time to do so much explaining about how these simulators work.  I would also like to give special thanks to jplumbley, who not only read and answered my almost endless questions in great detail, but who also gave great consideration to all my arguments.

So why did I build this simulator?  For the benefit of those who have managed to avoid my posts until now, I should mention that for many months, I have been building a large simulation of Chicago to scale.  I have tried to make it as realistic as possible, so it includes about 98% of all streets and roads, every highway, every rail line (passenger and elevated) and every park that is in the actual city.  All are exactly to scale, and all are in their actual places.  With a few exceptions, I also avoided adding anything that is not in the actual city.  And, very importantly, I zoned my city to match up as closely as possible with the real one.

Now using the available traffic simulators, this is not a recipe for success.  There are all sorts of good practices about where to put residences, where to put businesses and industry, how far apart zones should be, what a good road system should look like, etc.  But as these practices were designed for SC4, the great City of Chicago knows nothing about them, and so my simulation makes no effort to follow them either.  For the first few tiles, things went reasonably OK.  But as I began building more tiles farther from downtown, and their RCI populations became more and more unbalanced from SC4's perspective, things became more and more difficult.  The Sims needed to commute to downtown, where there were now more than a million vacant jobs.  But they wouldn't.  Instead, I got more and more buildings abandoned due to commute time too long, and things just really started going downhill.

At this time I was using CAM and the CAM traffic simulator.  When Simulators A and B came out, I tried them, but they only made things worse.  These are excellent simulators, but they simply weren't designed for long distance, multi-tile commuting.  The general opinion that I saw was that such a thing wasn't even possible in SC4.  After all, you have the eternal commuter problem, the time warp and all the weirdness it introduces, and then all the ramifications from the fact that different cities in a region are quite separate, and don't really have much communication with each other.  Nevertheless, I figured that by starting with the CAM simulator, which I was using because it worked best for me, and then tweaking it, I could get things to work a fair amount better than they were.

I succeeded in doing this, and actually accomplished a whole lot more than I originally thought was possible.  The first iteration of my simulator is now complete, and I have successfully tested it on all my cities.  It has the following features:

1. More realistic commute time.  I have adjusted the commute time to match real-world experiences.  As long as a region has suitable jobs for its Sims, they should be able to find them.  Multi-tile commuting works much better.  At this point, I can't say how much, as the developed part of my region is still relatively small.

2. More realistic zone placement.  This has been a bugaboo of SC4 from the beginning.  If you just placed zones willy-nilly where you felt like, all over the map, you usually got into trouble fast.  But real cities are like this; in the real world, you can't count on any particular placement of zones.  This simulator gives you much more latitude in where the zones are placed.

3. More realistic car usage.  I've seen figures that 88% of commuting in American cities is done by car.  In Europe, the figure is 78%, but it is fast approaching the American figure.  But you'd never know that looking at your typical Sim City.  The Maxis traffic simulator is heavily biased toward mass transit, and as far as I know, no one has tried changing that bias in a production traffic simulator.  I checked the traffic in my own cities via the Traffic Volume graph.  I always build excellent mass transit systems, but still, I was surprised at what I saw.  Among all my cities, car usage varied from 3% to 7% of total traffic.  Not very realistic at all.  So I increased car usage, and adjusted various other things to make it work seamlessly.  In my cities, this change resulted in increasing car usage by a factor of between 2.5 and 6, depending on the city.  In no city did car traffic reach 25%.  (I had the Commuter Shuttle Service Ordinance turned on for these tests, but as I describe below in the implementation section, it doesn't make a significant difference.)  Car traffic won't approach the real-world figure of 88% for anyone (at least not in this version  ;D ), but traffic is more in balance.  There have been no negative effects that I have been able to see as a result of this change; for example, Sims still walk to work whenever it's reasonable.

4. More realistic routing.  Due to the fact that the Maxis pathfinding algorithms don't pay much attention to route speed, realistic routing has always been a problem with traffic simulators.  In response, jplumbley had the clever idea to use congestion to force better routing in Simulators A and B.  This works very well, but has the unfortunate side effect of, well, congestion.  My simulator gets better routing than older ones (pre-2008) without forcing congestion.  I don't know how it compares to Simulators A and B, as I haven't done extensive testing of them.  I will be interested to find out how it does from people who test these simulators side by side.

5. Greatly reduced abandonment due to commute time problems.  As you might expect, this follows from the first point.  One of my all-time favorite quotes from this game is from someone who said, "These Sims are so stupid, they couldn't find a job if their lives depended on it!"  As I said in a recent post:
Quote
In the real world, you just don't see abandonment due to commute time.  Buildings may be abandoned due to lack of desirability or lack of demand, both of which occur in SC4 as well.  But not commute time.  Sure, individuals in a building may decide their commute is too long and move somewhere else, but the whole building?  Doesn't happen.
By adjusting the traffic simulator, I have been able to eliminate most of this problem.  In many of my cities, this problem no longer occurs at all.  In some of my "problem" cities (i.e., those where the layout of Chicago does not come close to matching SC4 guidelines), this type of abandonment has been greatly reduced to a small fraction of what it was before.  This problem can also be addressed in the area that the CAM people are working, and I'm going to be talking to them about this soon.  In the mean time, this problem is mostly gone.

6. Significantly faster execution.  In typical medium to large cities, the game runs more than twice as fast at high speed when this simulator is used, and the difference in speed grows as the population of the city grows.  The reason for this is that I have been able to eliminate some of the exponential properties of the pathfinder which are still present in Simulators A and B.  And since the traffic simulator accounts for only part of the time it takes to run the game, a doubling of total game speed means that the traffic simulator is running about three to four times faster.

7. Various transportation types are now more effective.  One of the side effects of the better routing in this simulator, which is different from Simulators A and B, is that Sims have a lot more flexibility in how they get to work and back.  Basically, all transportation types are more powerful; this has been done without making any significant changes to transportation speeds.  Previously, in many high-density cities it was necessary to create an entire grid of subways beneath the city to get acceptable performance.  The necessity for this type of layout has been greatly reduced, and subway layout can now be done according to more realistic standards.

----------------

So that's a summary of the new features in this traffic simulator.  I have tested it extensively in all my cities, which range from downtown areas where the commercial population outnumbers the residential 3 to 1, on through more mixed areas, and out to more medium-density, residential areas where there is very little commercial or industrial population.  The simulator works fine in all of these situations; there are no known bugs or problems.  There are clearly a whole range of environments that haven't been tested at all, but I have no reason to believe that the simulator will have any problems with them.  I will be explaining the implementation of the simulator in detail in future posts (don't you think this one is long enough?  :) ), but I wanted to announce it here and make it available for testing on a limited basis.  As this is really an alpha release at this point, I would like to invite interested members of recognized SC4D teams to try out this simulator.  If you are such a person and would like to try it out, send me a PM or an email with your team affiliation, and I'll send you a copy of the simulator.  Obviously, you need to remove your current simulator in order to run this one.  This simulator works fine in establishes cities; you should have no problem just dropping in this simulator and resuming your city.  You may see the traffic volume graph fluctuate for a few months as the simulator adjusts to the different mix of cars and other traffic, but then it will settle down into a stable pattern.  In the mean time, you should notice no ill effects on your city.

For those who would like a Park 'n' Ride version of this simulator, it's easy to create, or I can create one for you.

Right now, there's just one version of this simulator, which corresponds approximately to the Easy version of Simulators A and B.  At this point, I'm not creating Medium and Difficult simulators, though it's an issue I'm willing to consider; I think that for now, the overall game settings of Easy, Medium, and Hard should be sufficient for adjusting the challenge level.

No other changes to this game or changes to your playing style need to be made to use this simulator.  However, there is one main change I would recommend, especially if you're playing large urban cities and/or using CAM:

High capacity mass transit stations.  I have found that most mass transit stations in this game have too little capacity for their environments.  For details, please see my posts in Cogeo's Transportation Lots (http://sc4devotion.com/forums/index.php?topic=4854.20).  In my cities, I tend to use mostly cogeo's RTMT stations, along with a scattering of RaphaelNinja's five-way stations.  I would recommend doubling the capacity of RaphaelNinja's stations.  I have files with these capacities implemented if testers would simply like me to send them to them.  If you're using other stations, here are my recommendations for minimum capacities.  They are only approximate, of course.

Bus                    22,000
Subway              22,000
Bus + Subway     28,000
Passenger train    10,000 for Maxis-type station
                          5,000 per tile for inline stations
Elevated rail        20,000
Monorail             20,000

For multi-network stations, you should add about an additional 5,000 capacity for each addional network.  For stations on streets, you can divide the first three numbers by two; for stations on avenues, multiply them by two.

So that's it for now.  For those people who try the simulator now, I'm happy to hear about problems, but please hold off on questions about the implementation until I post my explanation, which will be when I get time.  (I hope to do this within the next week or so.)  Until then, those interested and qualified parties who would like to try this out should contact me.  Try it, I think you'll like it!
Title: Re: A new traffic simulator
Post by: z on August 02, 2008, 07:14:55 PM
There's a very important point I forgot to make in my first post:  This traffic simulator is in no way intended to replace Simulators A and B.  These latter simulators work extremely well in a wide variety of situations, and huge numbers of people are happy with them just as they are.  My simulator is intended simply to be another choice for people working in situations where its parameters are more appropriate for them than Simulators A or B.  What the exact range of those situations are remains to be seen.
Title: Re: A new traffic simulator
Post by: z on August 02, 2008, 08:35:14 PM
Q: Will this new traffic simulator work with existing NAM projects, such as NWM, RHW, and high speed rail?

A: Yes, it should be fully compatible with all of them.  Road capacities are normalized to fit the requirements of NWM.  Necessary parameters have been set properly to fit the requirements of RHW.  And though I haven't tested high speed rail, monorail has been tested and works fine, so high speed rail should as well.

Q: If I have further questions about compatibility, functionality, or usage, should I ask them now, or should I wait until you describe the implementation in full?

A: Feel free to ask any questions regarding compatibility, functionality, or usage at this point.
Title: Re: A new traffic simulator
Post by: z on August 03, 2008, 11:49:19 PM
This is the post explaining the traffic simulator implementation that I promised.  I will be going through the traffic simulator exemplar and explaining where the properties of my simulator differ from those of Simulators A and/or B, and why I made the decisions to change them to what they are.  As there are many changes, this is going to be a long post, so I'm going to add to it in stages.  In the interests of coherence, the additions will simply be edits to the original post.  Originally, I thought I might add a post to this thread notifying people when I had made an addition to the implementation description, but due to the lack of response to this thread so far, I think that may be excessive, and so for now I plan only to announce when the entire description is finished.  If people think I should add notification posts at each stage instead, please let me know.

I have based my implementation and the following description on my knowledge of the traffic simulator.  I have both read extensively what others have written in these forums and others, and performed numerous experiments myself.  Nevertheless, I may have gotten some things wrong.  If you see such an instance, please let me know.

Now on to the description...

Customers/Traffic Noise Coefficient - This number controls both the number of customers businesses receive due to traffic, measured as a function of traffic noise (a good thing), as well as the amount of traffic noise experienced by residences (a bad thing).  More customers means increased desirability for a commercial lot, while more noise means reduced desirability for a residential lot.  So the goal here is to balance this number to the point where businesses receive enough customers, but residential areas aren't too noisy.  Maxis set this number at .128, where it remains in Simulator A, while in Simulator B, it was reduced to .096.  Since my simulator increases the amount of cars significantly, and therefore the amount of traffic noise, I have found that a value of .04 works well here.

Network Speeds - Before getting into the actual speeds themselves, I would like to address the question of what units the speeds are in.  Some people have said that they are have no units associated with them, but various factors make it clear that these speeds are in kph.  Fortunately, the current simulators are all assuming speeds of kph, so it's not necessary to debate that issue here.  Instead, I'll just move on directly to the speeds themselves.  I have found that small changes in these speeds typically do not make much difference in the game, so what has been done here should not be weighted too heavily.  I started with the speeds from the CAM simulator and modified them where I felt appropriate.  As for the speeds themselves:

Walking - 15 kph on all networks where walking is allowed.
Driving - Roads: 50, Highways, 150, Streets: 30, Avenues: 50, One-Ways: 75, RHW: 150, Ground highway: 150.
Bus - Roads: 45, Highways, 150, Streets: 25, Avenues: 45, One-Ways: 65, RHW: 150, Ground highway: 150.
Passenger Train - 140.
Freight Truck - Roads: 40, Highways, 130, Streets: 25, Avenues: 45, One-Ways: 60, RHW: 130, Ground highway: 130.
Freight Train - 105.
Subway - 105.
El Train & GLR - 105.
Monorail, HSR, & BTM - 225.

In general, these speeds are fairly close to those in Simulators A and B, which differ slightly between each other.  I made bus speeds lower than car speeds to take into account intermediate bus stops, which are otherwise invisible to Sims.  I left bus speeds for highways the same as for cars because there are no bus stops on highways.  (RHW may be an exception, but I think any bus stops there are far enough apart not to matter.  I also decided to ignore the fact that if you put a bus stop next to a highway, some Sims will walk into the bus stop, climb up onto the highway, and jump onto the next passing bus.)

Many of the CAM simulator speeds are somewhat higher than the speeds in Simulators A and B, and even the corresponding speeds in real life, yet I left them unchanged.  There are two reasons for this.  First, I wanted to compensate at least somewhat for the limitations in the underlying traffic simulator algorithms.  Since these algorithms don't take speed adequately into account when determining a Sim's path, on average the paths will take longer than optimal.  Increasing speeds by a slight amount offsets this a bit.  Second, I discovered that all other things being equal, a network's speed plays a big role in the probability that Sims will use that network for inter-city travel; in fact, it plays even a bigger role than the math would suggest.  (I'll go more into this in the section on Commute Trip Max Time.)  So the slightly higher CAM speeds are quite useful.  I also felt that the proportion of the various network speeds to each other in the CAM simulator was rather realistic.

As for the other changes I made here, I knocked down the CAM avenue driving speed from 80 to 70.  This is still a little high, but it encourages Sims to use the avenues, which adds somewhat to both the realism and the workability of the simulator.  The other change I made along these lines has to do with elevated train speeds.  Once again, this comes down to the limitation of the traffic simulator algorithms that I just mentioned.  One thing people do to get around this limitation is to use a large network of subway lines beneath their cities, which tends to work very well.  But there are inevitably relatively few elevated rail lines above ground, and with all those intersecting subway lines available, the elevated rail lines don't tend to get used much.  By giving them a slight speed advantage, they get more realistic usage.

Travel strategy percent - This is where the changes were made to increase car usage.  The first of the four entries here is "Travel strategy percent WealthNone."  I'm not sure what that is - background traffic, maybe?  If anyone knows for sure, please post.  In any case, I left it alone.

The next three entries actually control normal commuting traffic choices.  They are described in detail on page 250 of the Prima guide.  Each entry has three numbers, which are the percent probability the Sim of that wealth category will use mass transit for his or her commute, the percent probability the Sim will use a car, and the percent probability that the Sim will choose the best route.  The manual says "fastest route," but of course it isn't necessarily the fastest, nor is it necessarily the shortest; it's simply the best route the simulator knows how to calculate.

The manual also implies that the simulator sticks to these percentages strictly, although it does mention that the Commuter Shuttle Service ordinance alters the numbers more in favor of mass transit.  It doesn't say how much, but my experience is that the difference is fairly small, maybe a few percent for each travel type.  But the implication that with this ordinance turned off, the simulator sticks to the specified percentages exactly is completely wrong.  The simulator treats these numbers as purely advisory.  It pays attention to them, but only to the extent it thinks is best.  Specifically, it will follow the recommendation if and only if that method can get the Sim to work within the Commute Trip Max Time.  Otherwise, it will use the other method, and add a penalty specified by by the Trip Starting Cost by Travel Type properties, which are described below.  The Pathfinding Heuristic also indirectly affects these probabilities by affecting how successful different travel strategies are.  It is also described below.

So here are the standard Maxis probabilities, which are present in all the simulators I have seen.  Each triplet of numbers represent percentage preference for mass transit, car, or best route:

R$      80,20,0
R$$    30,0,70
R$$$  10,80,10

And here are my set of numbers:

R$      70,30,0
R$$    20,70,10
R$$$  10,80,10

For one thing, I thought that these were much more realistic numbers, though still far below the typical percentages I mentioned in my first post.  Also, I noticed no deleterious effects on my cities from switching from the first set of numbers to the second one.  Notice that the numbers for R$$$ remain the same; I experimented with changing them to 5,90,5, but this did have a small negative effect in that my R$$$ population immediately dropped slightly.  As my other populations had not suffered from their changes, I thought I should leave the R$$$ numbers alone.

Although car usage did jump in my cities by a factor ranging from 2.5 to 6, what's interesting to note is how far the final traffic volume numbers were from the percentages above.  Using strictly those numbers, you would have expected to see about twice the car usage that I saw.  It is possible to enforce these numbers strictly using the abovementioned Trip Starting Cost by Travel Type properties, but as I discuss in their section below, it's not a good idea.  So for now, these seem like good numbers that produce a reasonable balance of traffic.

Pathfinding Heuristic - This is by far one of the most important numbers in the traffic simulator.  Basically, it's a measure of the accuracy of the pathfinding algorithm, which is what is used to determine a Sim's path to and from work.  The lower this number, the more accurate the algorithm.  Still, the accuracy of pathfinding in the game is limited by the nature of the algorithm used.  The one used in the traffic simulator primarily looks at distance, and tries to find the shortest path.  Speed is only a secondary consideration, although it does figure into the calculations.  So does traffic congestion, which of course has an effect on speed.

Instead of going through all the implications of this, along with the principles of heuristic pathfinding, I would refer the interested reader to mott's excellent dissertation on this topic, which can be found here (http://sc4devotion.com/forums/index.php?topic=2665.20) (mostly in the large post).  In terms of principles of operation, there's really nothing I can add that he hasn't already written.

Now that you are all experts on heuristic pathfinding, how does this apply to the game?  Well, we want the best pathfinding possible, which means the lowest number we can use for this paramater.  In the vanilla versions of the game, this parameter is set to 0.09, which results in very mediocre pathfinding at best.  With this number, Sims often do not find an optimal path from home to work, and as a result, the simulator may decide that commute time is too long and abandon a building, even if there are jobs within commuting range.  As mott pointed out, one big reason that Maxis chose such a relatively high number was that when this game was released in 2003, computers could not be guaranteed to have the processing power to handle lower numbers.  (More accurate pathfinding tends to take more CPU time, as you would expect.)

Once the NAM came out, lower numbers were tried for this parameter.  For example, the traffic simulator packaged with the CAM uses a value of 0.0465, which while still relatively high, is a big improvement over 0.09.  Then we come to the current simulators, A and B, which use values of 0.009 and 0.025, respectively.  (Since mott built Simulator B, and he also showed that a value of 0.003 resulted in essentially perfect pathfinding, I'm somewhat puzzled by why he chose such a relatively large value for his simulator.  Especially when he said, "Stick with the 0.003 heuristic for now, I'd say."  Does anyone know why?  Mott?)  Originally, I chose a value of 0.009 for my simulator, the same as is used in Simulator A.  Moving from CAM's 0.465 to 0.009 had immediate and dramatic results.  In one city, a traffic jam that had been present for literally centuries disappeared overnight.  Why?  What appears to have happened is that the simulator now spent more time finding the best individual route for each Sim, and this tended to spread traffic over a wider area.  In a similar vein, the simulator appeared to become smarter at avoiding congestion, again by spreading out traffic.  While doing so, it would find faster routes, and the speed of the routes became more significant.  Highways started becoming used more.  So traffic patterns as a whole became more realistic.

What about mott's magic number of 0.003?  As mott points out, for reasons which he details, CPU usage does not grow exponentially as this number declines.  In fact, it doesn't necessarily decline even linearly.  So I tried it out.  As expected, pathfinding became even more realistic.  So did commuting patterns as Sims started heading downtown from other tiles, even nonadjacent tiles.  I found one development to be particularly noteworthy.  I had already made the change to increase car usage in all my cities quite a while ago, but in my Downtown city, when I dropped the pathfinding heuristic to 0.003, car usage increased immediately even more, along with increased road congestion.  I found this rather puzzling, so I asked, "Why, O Perfect Pathfinding Algorithm, why is this happening?"  And it responded, "Look at the commute times, dummy."  Ignoring the insult from the algorithm, I looked at the commute times, and sure enough, they had dropped.  So the traffic simulator was now smart enough to figure out that by moving more Sims into cars, even at the expense of creating more traffic congestion, it could get them to work faster than by using my extensive mass transit system.  I was impressed.

As for performance, I found that in some cities, this value resulted in performance no worse than, and perhaps even a little better than, a value of 0.009.  I'm sure that mott would not be surprised.  Unfortunately, in other cities, performance took a big hit, so big, in fact, that the game spent almost all its time running the traffic simulator.  When this happens, Sim time does not move forward, and so this was unacceptable.

I went back to mott's posts and read through them again.  This time I noticed the part where he mentioned that having many steps in the congestion vs. speed curve (see below) could speed up the algorithm greatly.  So I added a number of more steps to my congestion vs. speed curve, without changing the shape of the curve.  Bingo!  I could now run with a pathfinding heuristic of 0.003 in my cities with quite acceptable performance.  Subjectively, it seems no worse anywhere than when I was using 0.009, and in some places it seems better.  So my present simulator uses the value of 0.003, which according to mott, results in the "perfect" version of the pathfinder.

I noticed that one city runs a fair amount slower than the others using a value of 0.003.  Depending on the results of wider testing, it may be wise to create two versions of the simulator (at least from the perspective of pathfinding), with one version using "better" pathfinding with a heuristic of 0.009, and the other using "best" pathfinding with a heuristic of 0.003.  There is certainly ample precedent for this.

Congestion to Accident Probability - I spent quite a bit of time researching this issue at the Google Institute of Traffic Engineering.  The final result I found was:  It depends.  It depends on what country you're in, which region of the country, whether it's rural or urban, what type of neighborhood if it's urban, what the weather is, what kinds of roads you're talking about, etc.  As you might expect, with all of these factors involved, there's a wide variation of plausible numbers.  Both the Maxis numbers and the numbers in Simulators A and B fall within the range of plausible numbers.  For simplicity's sake, I chose to stick with the Maxis numbers.

Network Traffic Capacity - This property is one of the most important in any traffic simulator, and this simulator is no exception.  The proper values for these capacities are dependent on many other properties in the simulator, though, so network capacities for one traffic simulator are not necessarily comparable to those of a different simulator.  This is especially true in the case of this simulator.  The capacities I have chosen here are all based on real-world capacities, yet they are much higher than for most traffic simulators in use.  This does not mean that this is a "super-easy" simulator.  To the contrary, I have verified that all network types can get congested beyond 100% capacity in a realistic city environment.

Essentially, higher capacities are required because this simulator, by being more realistic, produces more traffic.  For example, the Commute Trip Max Time is much larger in this simulator than in most others, leading to trips that are longer on average for most Sims.  Since the Sims are traveling longer times on all networks, this factor alone results in higher network traffic at any given time.  Furthermore, the higher Commute Trip Max Time makes it possible for more Sims to get to more jobs, further increasing traffic.  A third factor, which has been mentioned above, is that the change in the Travel Strategy Percent results in their being 2.5 to 6 times as many car trips as there would be in other simulators.  This number has a multiplicative effect on the previous number.  A fourth factor is that the intersection capacity effect is strengthened in this simulator, further slowing down traffic, and adding to the number of cars and buses on the road at any given time.  Finally, inter-city traffic is much more common, meaning that networks have to handle not only traffic from their cities, but sometimes significant amounts from neighboring cities as well.  All of these factors are designed to make the game more realistic, and they all result in network capacities that are more realistic as well.

With this in mind, here are the network capacities currently in use for all versions of this simulator.  As is customary, all capacities are expressed per tile.

[tabular type=2]
[row] [head]Network[/head] [head]Classic[/head] [head]Low[/head] [head]Medium[/head] [head]High[/head] [head]Ultra[/head] [/row]
[row] [data]Street[/data] [data]100[/data] [data]1500[/data] [data]2400[/data] [data]3600[/data] [data]7200[/data] [/row]
[row] [data]Road[/data] [data]1200[/data] [data]2400[/data] [data]4000[/data] [data]6000[/data] [data]12,000[/data] [/row]
[row] [data]Avenue[/data] [data]1400[/data] [data]2400[/data] [data]4000[/data] [data]6000[/data] [data]12,000[/data] [/row]
[row] [data]One-way Road[/data] [data]1800[/data] [data]3600[/data] [data]6000[/data] [data]9000[/data] [data]18,000[/data] [/row]
[row] [data]Rail[/data] [data]3000[/data] [data]10,000[/data] [data]16,000[/data] [data]30,000[/data] [data]65,200[/data] [/row]
[row] [data]Subway[/data] [data]3000[/data] [data]10,000[/data] [data]16,000[/data] [data]30,000[/data] [data]65,200[/data] [/row]
[row] [data]Elevated Rail[/data] [data]3000[/data] [data]10,000[/data] [data]16,000[/data] [data]30,000[/data] [data]65,200[/data] [/row]
[row] [data]Monorail[/data] [data]3000[/data] [data]10,000[/data] [data]16,000[/data] [data]30,000[/data] [data]65,200[/data] [/row]
[row] [data]RHW[/data] [data]2700[/data] [data]6000[/data] [data]10,000[/data] [data]15,000[/data] [data]30,000[/data] [/row]
[row] [data]Highway[/data] [data]4000[/data] [data]9000[/data] [data]15,000[/data] [data]22,500[/data] [data]45,000[/data] [/row]
[row] [data]Ground Highway[/data] [data]4000[/data] [data]9000[/data] [data]15,000[/data] [data]22,500[/data] [data]45,000[/data] [/row]
[/tabular]

Some of these figures may seem to be high, especially the rails.  But if you look at real-life rail lines they're actually quite reasonable.  For example, the new Second Avenue Subway in New York is designed to carry 600,000 passengers per day.  So if you were trying to simulate a real New York City, you couldn't do it, even with these capacities.  Fortunately, most people aren't building New York City, and the game doesn't require such high capacities.  But the capacities in this simulator do seem to fit in with actual game usage quite well.
Title: Re: A new traffic simulator
Post by: FrankU on August 04, 2008, 06:43:25 AM
Z,

You have been doing a lot of work! Wow!  &apls

I am curious of what this is leading to.
I am not a traffic simulator expert, know almost nothing of it, so I cannot help you, but I will surely follow the discussion.
Thanks for your elaborate work and explanations.
Title: Re: A new traffic simulator
Post by: b22rian on August 05, 2008, 09:01:00 PM
Hi Z....

You have put a lot of work and effort into all this.. and it looks like so far from reading your posts your doing
quite well with this.. I just wanted to thank you for providing more enjoyable playing options to this community..
What your doing trying to replicate the city of Chicago I find quite interesting and I hope you will continue
to update us with your progress with that..

also . especially considering what your doing yourself ..i do indeed understand your point about wanting to replicate
more closely real life city traffic conditions and transit modes.. No question your going to find those who would be happy to try out your new traffic simulator.. As you know there are those where realism is quite important to them and than you have others who sI'mply see what there doing as more a "game".. perhaps lost in their own visions of
what they have created or evolving towards.. Different strokes for different folks as they say..

In the region I'm working on now im currently using the Cam like you are using.. and traffic sim B on hard difficulty
currently most of my time has been spent on my largest city which is at about 700 K now.. I look forward to the challenges as i approach a million in population of keeping this at hard difficulty level for as long as I'm able to..
So far Ive been quite pleased actually with all the  mass transit types  and also the highway system i have created for car use.. There seems to be a very good balance in the way i have designed this city in terms of Mt versus car usage.. but obviously Ive had to design it that way once I was used to the traffic sim itself and how i saw the city evolving over time as it grew larger.. But so far Ive done a good job in terms of the fact i have seen very little abandonment due to commutes times or any traffic related problems.. Obviously these challenges will become more difficult as the city grows larger, but than thats a big reason i enjoy playing this game too.. In short i suppose I'm a player who is currently satisfied with what I'm working on ...

But having said that, you deserve a lot of credit for not only creating more enjoyable playing options for the people of this community.. but also in that your taking the time to explain what your doing.. providing important information about many aspects of this and your also doing it in a very thoughtful and articulate manner..
I just want you to know i appreciate what your doing with all this..
And when I'm ready to start a new city and region I would be more than happy to give your new traffic sim a go..
and provide you with as much feedback as my knowledge with all this will allow me to give you..

Thanks for all your time and efforts you have put into this so far..

Brian
Title: Re: A new traffic simulator
Post by: CasperVg on August 06, 2008, 01:56:51 AM
That looks like a very interesting traffic simulator. I would like to request, however, to create a (very) difficult version. I, for one, have always loved to use the Hard simulators, because I like to fix the issues that may arise from low capacities  :D
Title: Re: A new traffic simulator
Post by: z on August 06, 2008, 02:38:18 AM
That looks like a very interesting traffic simulator. I would like to request, however, to create a (very) difficult version. I, for one, have always loved to use the Hard simulators, because I like to fix the issues that may arise from low capacities  :D
I have been thinking more about other versions, and I have some ideas.  Not by lowering capacities, but by making it even more realistic.  Instead of 20% to 25% cars, 80% cars!  (With no added road capacity; it's already realistic in this simulator.)  Multiply the cost of subway tiles by 50.  Make intersections really act like intersections (they don't now) and slow down road traffic even more!  All of these are just extra realism (and they are very realistic), but they would give you a very difficult version, to be sure.  A version of intermediate difficulty would then also be possible.
Title: Re: A new traffic simulator
Post by: FrankU on August 06, 2008, 03:26:20 AM
Make intersections really act like intersections (they don't now) and slow down road traffic even more! 

 &idea
Do you mean by this that intersections do not slow down commute time? Meaning that it is not important wether I put two or twohundred intersections between my house and my office? Well, that is really unrealistic. It would be nice if you could change that. There even could be a difference in capacity and speed between intersections with or without streetlights, roundabouts, threeway, fourway etc....
Title: Re: A new traffic simulator
Post by: CasperVg on August 06, 2008, 03:47:07 AM
I have been thinking more about other versions, and I have some ideas.  Not by lowering capacities, but by making it even more realistic.  Instead of 20% to 25% cars, 80% cars!  (With no added road capacity; it's already realistic in this simulator.)  Multiply the cost of subway tiles by 50.  Make intersections really act like intersections (they don't now) and slow down road traffic even more!  All of these are just extra realism (and they are very realistic), but they would give you a very difficult version, to be sure.  A version of intermediate difficulty would then also be possible.

That sounds like heaven!  ()stsfd()
Title: Re: A new traffic simulator
Post by: z on August 06, 2008, 04:22:33 AM
&idea
Do you mean by this that intersections do not slow down commute time? Meaning that it is not important wether I put two or twohundred intersections between my house and my office? Well, that is really unrealistic. It would be nice if you could change that. There even could be a difference in capacity and speed between intersections with or without streetlights, roundabouts, threeway, fourway etc....
For the most part, they don't.  The traffic simulators handle intersections by temporarily reducing network capacity.  By default, it's reduced by 30% in the intersection square, 20% one square away, and 10% two squares away.  Simulators A and B are even more lenient than this.

Note that the speed is not reduced (at least not directly), only the capacity.  So if a road intersection is at 70% or less of capacity, the Sims don't even take their foot off the accelerator as they zoom through.  This is regardless of how many pretty stoplights you have at the intersection and what the automata look like they're doing.  And even if the network is running at a higher capacity, the Sims just slow down a bit; only in highly congested traffic do they slow down significantly, and even then, typically just for a square or two.  They never stop, much less wait for an entire stoplight cycle.  If I were a policeman in Sim City, I could make a simulated fortune writing tickets to Sims who run red lights, because they all do, every time.  At busy intersections, they just do it a bit more slowly than at others.

Now it's not possible to actually make the Sims stop at intersections.  But it is possible to drop the intersection capacity numbers down far enough to have the same effect.

Meanwhile, the easiest way to see the effect of intersections is to look at the Traffic Congestion View.  For any intersections that are pure green, your Sims are driving through them as if they're not there.
Title: Re: A new traffic simulator
Post by: FrankU on August 06, 2008, 06:16:50 AM
Aha!
Thanks.

So now I also know why SC shows us traffic accidents instead of waiting rows at congested streets. They don't stop, so they clash into each other.  $%Grinno$%
But that is quite an unrealistic simulation then. Especially because the sims won't search for another route as to avoid the congested sqares.... They just jump on each other's necks on the intersection and crash their respective cars.... Not too smart..

One disappointment for you though: your sims won't stop, so they aren't able to receive the tickets and as there is no postal system in SC4 (have you ever seen a post office?) you cannot send the tickets by post.  ()what()
Title: Re: A new traffic simulator
Post by: Rayden on August 06, 2008, 10:34:45 AM
Aha!
Thanks.

So now I also know why SC shows us traffic accidents instead of waiting rows at congested streets. They don't stop, so they clash into each other.  $%Grinno$%
But that is quite an unrealistic simulation then. Especially because the sims won't search for another route as to avoid the congested sqares.... They just jump on each other's necks on the intersection and crash their respective cars.... Not too smart..

One disappointment for you though: your sims won't stop, so they aren't able to receive the tickets and as there is no postal system in SC4 (have you ever seen a post office?) you cannot send the tickets by post.  ()what()

I'm sure Equinox's post office would manage that ;) - http://www.simtropolis.com/stex/index.cfm?id=15266http://www.simtropolis.com/stex/index.cfm?id=15266

Good work z, I'm following this with great interest. :thumbsup:
Title: Re: A new traffic simulator
Post by: z on August 06, 2008, 03:55:40 PM
Aha!
Thanks.

So now I also know why SC shows us traffic accidents instead of waiting rows at congested streets. They don't stop, so they clash into each other.  $%Grinno$%
But that is quite an unrealistic simulation then. Especially because the sims won't search for another route as to avoid the congested sqares.... They just jump on each other's necks on the intersection and crash their respective cars.... Not too smart..
Actually, this is not the way it works.  Accidents are purely a function of congestion.  There's a table in the traffic simulator that links the level of congestion to the probability of an accident.  So accidents aren't specifically tied to intersections, other than by the level of congestion at the intersection.

Also, when any route gets congested enough (including intersections), the simulator does start looking for alternate routes.  Intentional use of congestion for this purpose is one of the main features of Simulators A and B.

Quote
One disappointment for you though: your sims won't stop, so they aren't able to receive the tickets and as there is no postal system in SC4 (have you ever seen a post office?) you cannot send the tickets by post.   ()what()
I'm sure Equinox's post office would manage that ;)

It sure does, and it's sitting right in my downtown Chicago, where it belongs.  It's a really cool building - have you ever driven through a post office on an expressway?  I was fortunate emough to have done this may times when I still lived in Chicago.
Title: Re: A new traffic simulator
Post by: Rayden on August 06, 2008, 07:23:53 PM
It sure does, and it's sitting right in my downtown Chicago, where it belongs.  It's a really cool building - have you ever driven through a post office on an expressway?  I was fortunate emough to have done this may times when I still lived in Chicago.

That's why I mentioned that one, coz it's in Chicago, and you are doing a Chicago "replica", but there is also around, some other post offices, even a postal delivery service lot, somewhere on the LEX. :thumbsup:
Title: Re: A new traffic simulator
Post by: b22rian on August 06, 2008, 08:44:12 PM
i think using Mott's traffic sim on hard difficulty is somewhat challenging..

Eventually if you keep increasing the population higher and higher you find the challenge your looking for

but i suppose it takes time.. the largest city i have now is a Little over 700 K and I'm starting to get a few network

lines congested now..
Title: Re: A new traffic simulator
Post by: b22rian on August 21, 2008, 09:08:22 PM
Actually, this is not the way it works.  Accidents are purely a function of congestion.  There's a table in the traffic simulator that links the level of congestion to the probability of an accident.  So accidents aren't specifically tied to intersections, other than by the level of congestion at the intersection.


Yup,  a lot of time hearing those accidents happening also tips me off to congestion on my roads and stuff..

Brian
Title: Re: A new traffic simulator
Post by: redraider147 on August 26, 2008, 04:43:36 PM
ok so lets bring some of my test results to the public....

1. one interesting side effect that i've been able to reproduce over and over again is that my game and cities load twice as fast (if not faster) than before when i was using the NAM traffic simulators...curious...it was the only thing changed.

2. while commute time dropped only slightly over NAM simulator AP, traffic volume decreased, congestion decreased, and population increased. how if all my transportation volume categories decreased is my population rising?

3. my population is increasing, but the amount of abandoned buildings is increasing (all due to commute time)...weird...and commute times are decreasing from before...

4. one curious thing i noticed is that my sims take the freeway to work, but not home...ramps are exactly the same on both sides as i use the feeder road system. they all want to take avenues home from work...

5. is there a park and ride aspect that i might be missing? that seems like it should be my problem...it looks like what happened when i installed the AP simulator and hadn't placed parking garages and lots...


More results to come...
Title: Re: A new traffic simulator
Post by: The_Wind on August 26, 2008, 07:30:06 PM
hmmm this sounds very intresting, i hope i can see it realesed.
Title: Re: A new traffic simulator
Post by: b22rian on August 26, 2008, 07:45:27 PM
ok so lets bring some of my test results to the public....


2. while commute time dropped only slightly over NAM simulator AP, traffic volume decreased, congestion decreased, and population increased. how if all my transportation volume categories decreased is my population rising?




Hi red raider thanks for posting some comparisons of the 2 traffic simulators..
but which nam sim is AP ?
Is it one of the new traffic sims from mott and j plumbley A and B with the 3 different levels of difficulty or another
older nam one perhaps ?

Thanks Brian
Title: Re: A new traffic simulator
Post by: z on August 26, 2008, 07:59:33 PM
ok so lets bring some of my test results to the public....

1. one interesting side effect that i've been able to reproduce over and over again is that my game and cities load twice as fast (if not faster) than before when i was using the NAM traffic simulators...curious...it was the only thing changed.

I have no idea why this is happening.  There is nothing in any traffic simulator that I know of that would cause this, so I can't take credit for it.

Quote
2. while commute time dropped only slightly over NAM simulator AP, traffic volume decreased, congestion decreased, and population increased. how if all my transportation volume categories decreased is my population rising?

3. my population is increasing, but the amount of abandoned buildings is increasing (all due to commute time)...weird...and commute times are decreasing from before...

This all makes sense if you understand how the game works.  Commute time decreases because I'm using a more efficient pathfinding engine than Simulators A or B.  But you have to go by relative commute times, because the absolute numbers aren't scaled correctly in all the simulators.  I'll send you a version that has commute times scaled correctly in actual Sim minutes for this simulator.

Congestion is greatly decreased because network capacities are larger, and pathfinding is better.  Add all of these things together, and the result is less traffic (which to some extent, further reduces congestion).  The Sims are traveling shorter and often faster routes, and spending less time on them.  Since there's less traffic, there's less traffic noise and less pollution, both of which increase residential desirability.  So your population starts increasing.  The system has extra capacity built into it, so you still have less traffic than you started with.  But now you have more Sims.  Where are they going to work?  Max commute time is set very high, so your Sims can get to work almost anywhere.  So there are two possibilities I know about that could explain your building abandonment:  1) You don't have enough jobs for your larger population, so you'll run out the commute time clock, no matter how high it's set, before they find jobs, because there are no more jobs to find.  Or 2) You may have hit the CAM Demand Bug, which will produce the same results.  This bug is being fixed in CAM 2.0, which should be entering beta testing soon.

Quote
4. one curious thing i noticed is that my sims take the freeway to work, but not home...ramps are exactly the same on both sides as i use the feeder road system. they all want to take avenues home from work...

This is completely normal behavior for Sims.  As long as routes get them to or from work in similar amounts of time, they aren't too picky about which ones they take.

Quote
5. is there a park and ride aspect that i might be missing? that seems like it should be my problem...it looks like what happened when i installed the AP simulator and hadn't placed parking garages and lots...

The version I sent you is not a Park and Ride version.  And to answer Brian's question, the AP simulator is Simulator A with Park and Ride enabled.

hmmm this sounds very intresting, i hope i can see it realesed.

I assure you that at some point it will be released, either here, on the STEX, or both.
Title: Re: A new traffic simulator
Post by: The_Wind on August 26, 2008, 09:01:36 PM
i have a question, what will this do for inter0tile commute times? in somecities while using simulator a or b i would have area's that would addandone dew to commute times, when my commute time was say around 60+ max. is this normal? or rare? And what would you simulator do for that?
Title: Re: A new traffic simulator
Post by: b22rian on August 26, 2008, 09:48:17 PM

2) You may have hit the CAM Demand Bug, which will produce the same results.  This bug is being fixed in CAM 2.0, which should be entering beta testing soon.



Z,
Ive seen you mention about this bug before.. Can you explain exactly what it involves, or direct me to a thread
which explains about it when your not too busy ..

Thanks Brian
Title: Re: A new traffic simulator
Post by: z on August 26, 2008, 10:49:30 PM
@b22rian: Who better to explain this bug than RippleJet himself?  You can read his explanation at http://sc4devotion.com/forums/index.php?topic=2488.msg159401#msg159401 (http://sc4devotion.com/forums/index.php?topic=2488.msg159401#msg159401).  If you want the full context of the discussion, you need to start at the last post on the previous page.

i have a question, what will this do for inter0tile commute times? in somecities while using simulator a or b i would have area's that would addandone dew to commute times, when my commute time was say around 60+ max. is this normal? or rare? And what would you simulator do for that?

One of the main design goals of my simulator was to improve intercity commuting.  Simulators A and B simply don't have a high enough max commute time to support large scale intercity commuting.  As for your commute time number, the number you see in the graph is in itself not too meaningful, because it's not scaled correctly in Simulators A and B.  Using the Maxis scale of 64 squares = 1 km, the maximum one-way commute time in these two simulators is 8.5 and 12 minutes, respectively.  That's large enough to accomplish the commute goals jplumbley describes, but for longer commutes, it's just not sufficient.  My simulator supports much longer commute times, which leads to far less abandonment due to commute time.  Theoretically, it should eliminate abandonment due to commute time if the rest of your city and region is played properly (not an easy task), but the aforementioned CAM Demand Bug will have to be fixed before I can see if that actually happens.  In the mean time, make sure you have enough jobs of the proper type for your Sims.

Whether abandonment is normal or rare depends on many things.  It is quite possible to use Simulators A or B on a large tile and have little or no abandonment; xxdita has a thriving city of eight million Sims using one of these simulators.  But you have to be careful about the way you plan and lay out your city.
Title: Re: A new traffic simulator
Post by: redraider147 on August 27, 2008, 01:08:17 AM
The CAM bug appears to be the problem...this is my first region with it and this is the largest city i'm having problems in. if this is the case, to accurately see the affects of the simulator, one must remove the mod, or wait for it to be fixed....i'm not about to remove it as i have many buildings in my city from the CAM. plus the face that i am trying for a simlympic bid with a city that wasn't created for a city journal, and i seem to see my city developing naturally the way i was hoping it would, i likely will wait til v2.0 is released.
Title: Re: A new traffic simulator
Post by: z on August 27, 2008, 03:16:36 AM
I agree - I certainly wouldn't recommend removing CAM.  I think what's happened to you is very similar to what happened to me - namely, this simulator improves traffic flow to the point where the CAM demand bug becomes a much more significant obstacle to growth.  For this reason, I'm going to hold off any general release until this bug is fixed, which shouldn't be too long.  A working fix has actually been demonstrated, and it's just a question of getting it automated and wrapped into the CAM 2.0 release.  Part of this may actually be done already.  I'll keep everyone informed as to progress in this area.
Title: Re: A new traffic simulator
Post by: b22rian on August 27, 2008, 05:54:13 AM
thanks Z,

for providing me with the thread of the cam demand bug..
I havent noticed any problems with my city (residential pop is close to 1 million now..)
But by examining my city i see why I havent..its because i have about double the job supply compared
to the work force in my city.. I always play having a large commercial job supply because i like having
a dense commercial district with lots of high rises in my cities..But I had a look at my CRF version 2 and
currently demand for R $$$ is actually higher than either R $$ or R $... Although compared to your example
city you had in the cam thread i have a little less % of the population being R $$$ compared to what you
showed maybe about 8- 9 % compared to the 10 %..you showed.. My current tax rate for R $$$ is actually
higher than the other 2.. R $$$ is 6.4 % compared to 5.5 % for both R $$ and R %.. which is interesting..
But the main reason i think I currently have such a high demand for R $$$ is the amount is huge CO $$$ and
CO %% high rises i have which is a lot !, thus a high work supply.. for R $$$ residents..

so I was just lucky, its really my style of play which compensates for the demand bug with Cam you found..
But I do understand your guys frustrations with it, because prolly you dont want so many job zones in your
city.. Especially you Z i understand because your trying to replicate Chicago as accurately as you can..
Hopefully as you said at least a beta release of cam 2.0 will come out soon..

Also sorry I'm drifting away from the subject matter of this thread which is supposed to be about your new
traffic sim.., But I think.. like you guys, best for me would be to start a new city with your new traffic sim , Z and
hopefully cam 2.0.. although it sounds like I may have to change my playing style a bit with the way i build too
much commercial zoning.. Although I think it would be interesting for testing purposes still at some point to use
your new traffic sim with my current city, and than we can make another useful comparison such as red raider
posted..?  Since my largest city is quite large and uses a wide range of transport networks..

My apologies, Brian
Title: Re: A new traffic simulator
Post by: Diggis on August 27, 2008, 06:04:25 AM
One of the main design goals of my simulator was to improve intercity commuting.  Simulators A and B simply don't have a high enough max commute time to support large scale intercity commuting.  As for your commute time number, the number you see in the graph is in itself not too meaningful, because it's not scaled correctly in Simulators A and B.  Using the Maxis scale of 64 squares = 1 km, the maximum one-way commute time in these two simulators is 8.5 and 12 minutes, respectively.  That's large enough to accomplish the commute goals jplumbley describes, but for longer commutes, it's just not sufficient.  My simulator supports much longer commute times, which leads to far less abandonment due to commute time. 

I may be wrong, but as I understand it once the commuters reach a city limit their commute is reset.  This is due to the cities being autonomous and one not checking another cities files.  All they do is see X commuters coming in from city A, but not how far they have travelled before getting to the city border.  If they find a job closer to their point of entry than another city border then they'll stop there.  If the commute time is long enough to cross one full city, then won't it be enough to cross more?   ()what()
Title: Re: A new traffic simulator
Post by: Shadow Assassin on August 27, 2008, 07:18:44 AM
Quote
If the commute time is long enough to cross one full city, then won't it be enough to cross more?

It depends on what's going on in that city tile...
Title: Re: A new traffic simulator
Post by: z on August 27, 2008, 01:53:42 PM
I may be wrong, but as I understand it once the commuters reach a city limit their commute is reset.  This is due to the cities being autonomous and one not checking another cities files.  All they do is see X commuters coming in from city A, but not how far they have travelled before getting to the city border.  If they find a job closer to their point of entry than another city border then they'll stop there.

This part is definitely true.

Quote
  If the commute time is long enough to cross one full city, then won't it be enough to cross more?   ()what()

Here's where things get interesting.  It appears that this is true, but only in cities beyond their original city.  Through numerous experiments I have found that if Sims start out in one city, their chances of being able to cross a border into an adjacent city are directly related to how far they'll be able to travel in that new city on their current network.  So, for example, as you raise the Commute Trip Max Time property in the simulator, you see more and more intercity traffic by rails (typically subways for me), which are the fastest form of transport.  (This assumes you have sufficient demand in your adjacent city.)  But cars still don't cross the border very often.  If you raise Commute Trip Max Time enough, cars start streaming across the border in large numbers as well.  So since I want to support intercity commuting, I've raised Commute Trip Max Time to this latter point, which is more than an order of magnitude higher than that used in Simulators A or B.

As to what happens to these Sims when they enter the second city, they definitely seem to have enough commute time to cross the whole city, and I've seen them enter a third city.  So from the data I have so far, it seems that if they have enough commute time to make that initial crossing, they should be able to continue traveling through cities until they find an appropriate job.
Title: Re: A new traffic simulator
Post by: The_Wind on August 27, 2008, 03:40:15 PM
hmmm thank you for awnsering, this simulator you are planning sounds very nice, hope for the best :thumbsup:
also i can be a tester if you need, seeing as im just starting up a new region.
Title: Release of Traffic Simulator Z - Alpha 1 version
Post by: z on October 04, 2008, 05:39:41 PM
In an earlier post, I said I was going to hold off releasing any version of my traffic simulator until the CAM demand bug (exlplained above) had been fixed.  I have decided not to wait until then for three reasons:  1) The effect of the CAM demand bug is not that great; it's simply slightly more visible in this simulator than in others because of the increased maximum commute time.  But even in the worst cases, I find that that for large cities spanning multiple tiles, this simulator works better for me than Simulators A or B.  2) I've received reports back from my single tester, who has also encountered the CAM demand bug, but still prefers this traffic simulator to any other.  3) I keep getting numerous requests to release this simulator.

Finally, for many people the CAM demand bug will not be very visible, or will not be visible at all - especially if you don't use CAM!  So I have decided to release an alpha version of this simulator.  Although it is an alpha version, I have been running it for months on my system with no problems at all.  So there are no known bugs.

As I've mentioned in previous posts, this simulator uses values for many parameters that are very different from those in Simulators A and B.  The main criterion in picking these parameters was to make them as close to what is found in the real world as possible.  I have gone into detail about a number of these parameters in an earlier post; I will finish that post when I have more time.  (Right now, I'm working on getting the next version of RTMT finished; I'll have the necessary time when that's done.)  My tester says that he sees "a much more realistic traffic pattern" with this simulator; that is my experience as well.

Right now, there is only one version of this simulator; additional versions (as with the current simulators) will be available later in the development process.  This version should work fine in all sizes of cities.  It is completely compatible with NAM, CAM, RHW SAM, etc.  The simulator is compatible with most of the NWM roads, except for the TLA and OWR-5 roads.  These roads will still work; they will simply be very heavily congested in highly trafficked areas.  But NWM is not released yet; by the time it is, there will be a version of this simulator that works perfectly with all forms of NWM.

As this simulator uses high capacity networks, it requires high capacity mass transit stations for optimal performance.  I would recommend the current version of RTMT (http://sc4devotion.com/csxlex/lex_filedesc.php?lotGET=1057) for this purpose.  When installing, I would recommend using the CAM capacity setting.  If you do this, then after the install, replace the Stations file with the identically-named file in the attached zip archive; it is specifically tuned to this simulator.  If you already have RTMT installed, you can still replace your Stations file with the one in the archive.

To install this simulator, first remove any other traffic simulator you are using, as well as any version of my Traffic Volume View.  Also remove the file NetworkAddonMod_Congestion_Data_View.dat if you have it installed.  Then extract the first two files in the archive into your Network Addon Mod folder.  You can switch to this simulator in an existing city or in a new city; it doesn't matter.  If you try it and don't like it, you can switch back to your old simulator.

As this is an alpha release, there is limited support available for it, largely due to my lack of time.  But comments in this thread are welcome, and I will answer those questions which seem to be most important.  So here it is - enjoy!

EDIT:  This version of the traffic simulator has been superseded.  You can get the current version here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=4809).
Title: Re: A new traffic simulator
Post by: MassHelper on October 04, 2008, 05:47:57 PM
So can u list the capacity changes from this new traffic plugin???
Title: Re: A new traffic simulator
Post by: z on October 04, 2008, 09:54:40 PM
So can u list the capacity changes from this new traffic plugin???

A very reasonable question, indeed.  Network Traffic Capacity was the next section I was going to add to my post on implementation details, so I decided I might as well do it now.  You can find the section on Network Traffic Capacity at the bottom of this post (http://sc4devotion.com/forums/index.php?topic=5382.msg170440#msg170440).  The reason I am not just listing the numbers here is that they are not directly comparable to those of other traffic simulators, for reasons which I explain in the post.  So by reading the new section, you'll see all the numbers, but you'll also see the context in which they work.
Title: Re: A new traffic simulator
Post by: MassHelper on October 04, 2008, 10:46:33 PM
Hey, Z thx for the notice....

Is the value for the cap in street 15K....??? I hope the 1,500 is not a typo... (That cap would be over in a day in the simulation)...
Title: Re: A new traffic simulator
Post by: z on October 04, 2008, 10:58:53 PM
No, the 1,500 is not a typo.  This capacity is an eighth of the road capacity; in the original Maxis traffic simulator, streets were a tenth of road capacity, so this proportion is fairly close.  If you look at the difference between streets and roads in real cities, I think you'll see that this proportion is pretty reasonable.
Title: Re: A new traffic simulator
Post by: MassHelper on October 05, 2008, 12:38:36 PM
Oops...

Anyway... Is this simulator compatible with Simulator A or B in Apr. 08 NAM???

;) Mass
Title: Re: A new traffic simulator
Post by: MassHelper on October 05, 2008, 04:10:45 PM
So... wat's the final outcome???  :-[

Should I use Z's simulator add-on or keep on using Simulator A/B???

:) Mass
Title: Re: A new traffic simulator
Post by: z on October 05, 2008, 10:04:36 PM
Anyway... Is this simulator compatible with Simulator A or B in Apr. 08 NAM???

;) Mass

If you take a city you've built with Simulator A or B and drop in this new simulator, everything should work fine.  If you continue building your city the way you had been with Simulator A or B, then you can switch back to that simulator at any time with no ill effects.  I have verified this through testing.  Is there anything else you mean by "compatible"?
Title: Re: A new traffic simulator
Post by: z on October 05, 2008, 10:37:48 PM
Just to make things clear:  No one's talking about running multiple simulators at the same time.  My installation instructions specifically state that any other traffic simulators need to be removed first.  And at the top of my previous post, I use the word "switch" when addressing the compatibility issue.  I had assumed that MassHelper was talking about the ability to switch back and forth between simulators when he asked about compatibility.  If he (or anyone else) wants to run multiple traffic simulators simultaneously, obviously, you can't do it.
Title: Re: A new traffic simulator
Post by: Tarkus on October 06, 2008, 02:39:28 AM
Well, I've done a little preliminary testing on the new "Simulator Z" (as I will call it), and have compared it with data obtained from "Simulator A Hard", and have a few observations--I'll have a little bit more detailed report in a bit, with some pics.

-The region I used for testing has most of its population (roughly 160,000) spread across three adjacent city tiles, which have two routes that travel the entire length of them--one being an RHW (mostly an RHW-4, with the occasional RHW-6S setup for merge lanes at interchanges), the other being an Avenue/TLA-5. There is absolutely no mass transit of any kind in the region.

-With both the "A Hard" and "Z" Simulators, I have noticed sims commuting across multiple city tiles.  The Sims tended to utilize more of the neighbor connections.  Neither resulted in any commuter loops.  The "A Hard", however, did actually seem to allow the commuters to go further into the final city tile of the commute.

-Most of the congestion I saw with "A Hard" was along arterial routes, whereas it was at Street intersections with the "Z" Simulator.

-Simulator Z seemed to result in higher pedestrian traffic volumes for the most part.

-Simulator Z does indeed exhibit an additive congestion calculation (Morning+Evening), which I was able to clearly discern with my modified Congestion DataView (attached here, in case anyone wants to try it--it goes down to 25% and uses a really radical color ramp). 

-The actual Commute Time Graph display showed a dramatic difference--it was dramatically lower with the "Z" Simulator, though this may simply be an the result of the way in which "A Hard" is relaying commute time info to the graph (this would make sense in light of the fact that the Trip Length To Minutes Multiplier is set to 1 in Simulator Z, and 10.54 in Simulator A Hard).

-I have also had a chance to test Simulator Z on both wider RHWs (an RHW-8) and NWM networks (TLA-5s).  I didn't really notice anything with the TLA-5s, as they were nowhere near the theoretical capacity (I'd have to lower the Road Capacity in order to have a more conclusive reading). 

The RHW-8, however, did not function correctly with Simulator Z installed.  Using the RHW-8 with the "A Hard" Simulator allows for a "spreading" effect upon reaching the wider stretch, in which the overall traffic volume is split between the two tiles that make up each half of the highway, as would happen in RL.  With Simulator Z, however, the traffic stayed on the "inside" tile and never attempted to cross over--in effect, the Simulator Z is not compatible with the wider RHWs. 

This is an issue that qurlix, my predecessor on the RHW, ran into when he created an RHW-10 prototype while using the old NAM Simulators.
Overall, Simulator Z struck me as functioning much like the old NAM Simulators (which were basically based upon the same engine as the Maxis, with difference in capacity and pathfinding efficiency), but with a much longer range.  A and Z seemed to ultimately result in some fairly similar patterns in terms of the routing through the region, but the "bottlenecks" in the system were in drastically different places.

I'll have some hard data to show a bit later.

-Alex (Tarkus)
Title: Re: A new traffic simulator
Post by: z on October 06, 2008, 04:24:55 AM
Thanks for your comments, Alex - I found them quite helpful.  In response, I have some comments and questions of my own.

-With both the "A Hard" and "Z" Simulators, I have noticed sims commuting across multiple city tiles.  The Sims tended to utilize more of the neighbor connections.  Neither resulted in any commuter loops.  The "A Hard", however, did actually seem to allow the commuters to go further into the final city tile of the commute.

When you say, "The Sims tended to utilize more of the neighbor connections," are you talking about both of these two simulators, or just Simulator Z?

The last sentence is somewhat unexpected, given the longer range of Simulator Z.  Do have any idea what would account for this?  It's possible that it's an artifact of the way your test region is set up; more data from others would be helpful here.

Quote
-Most of the congestion I saw with "A Hard" was along arterial routes, whereas it was at Street intersections with the "Z" Simulator.

Yes, I have the intersection effect tuned up a bit higher.  I don't have a lot of intersecting streets, so I didn't notice this as much as you did.  I may have to tone the intersection effect down a bit here.

Quote
-Simulator Z seemed to result in higher pedestrian traffic volumes for the most part.

I've noticed this too; I'm pretty sure it's a direct result of the higher maximum commute times.

Quote
-Simulator Z does indeed exhibit an additive congestion calculation (Morning+Evening), which I was able to clearly discern with my modified Congestion DataView (attached here, in case anyone wants to try it--it goes down to 25% and uses a really radical color ramp). 

Yes, this is how the vanilla Maxis traffic simulator works, too.

Quote
-The actual Commute Time Graph display showed a dramatic difference--it was dramatically lower with the "Z" Simulator, though this may simply be an the result of the way in which "A Hard" is relaying commute time info to the graph (this would make sense in light of the fact that the Trip Length To Minutes Multiplier is set to 1 in Simulator Z, and 10.54 in Simulator A Hard).

The Trip Length To Minutes Multiplier doesn't do anything at all.  Simulator Z comes with its own Commute Time Graph exemplar attached (as mott recommended); the Graph Plot Scale property is what actually determines the graph scale.  I used mott's formula to calculate the number I use for my simulator.  The numbers would be expected to be lower than the standard graph, as Commute Trip Max Time is only 8.5 minutes (one way) in Simulator A.  It's possible that mott's formula is not correct, though, in which case Graph Plot Scale  would have to be adjusted.

Quote
-I have also had a chance to test Simulator Z on both wider RHWs (an RHW-8) and NWM networks (TLA-5s).  I didn't really notice anything with the TLA-5s, as they were nowhere near the theoretical capacity (I'd have to lower the Road Capacity in order to have a more conclusive reading). 

Well, that's encouraging; if I moderate the intersection effect a bit, as I mentioned above, that may be all that's necessary to get it to work with TLA's.

Quote
The RHW-8, however, did not function correctly with Simulator Z installed.  Using the RHW-8 with the "A Hard" Simulator allows for a "spreading" effect upon reaching the wider stretch, in which the overall traffic volume is split between the two tiles that make up each half of the highway, as would happen in RL.  With Simulator Z, however, the traffic stayed on the "inside" tile and never attempted to cross over--in effect, the Simulator Z is not compatible with the wider RHWs. 

This is quite unfortunate.  I had not tried the simulator with RHW-8.  Clearly, I need to fix this.  Does this work with Simulators A and B simply because of the difference in the Congestion vs. Speed curve?  Or is there something else responsible?  Approximately what capacity were these roads running at when you noticed this?

Quote
Overall, Simulator Z struck me as functioning much like the old NAM Simulators (which were basically based upon the same engine as the Maxis, with difference in capacity and pathfinding efficiency), but with a much longer range.  A and Z seemed to ultimately result in some fairly similar patterns in terms of the routing through the region, but the "bottlenecks" in the system were in drastically different places.

When you say "same engine," I'm a little confused.  Isn't there only one engine, namely the Maxis simulator code, with all the simulators merely being adjustments of various properties belonging to it?

My overall results have been different, undoubtedly due to the difference in the cities involved.  When Simulators A and B first came out, I thought, "Great!  I could really use a better simulator!"  So I started running Simulator A (Easy) in one of my cities, which promptly started to fall apart.  So I backed it out.  This is what led to the creation of Simulator Z.

One thing your results do seem to confirm, though, is something that I said early on in this thread:  that Simulator Z is not designed to be a replacement for Simulators A and B.  I think that each simulator has its strengths in certain situations.  You've also identified some areas I need to work on, for which I'm grateful.  It will also be very useful to hear from other people using this simulator in different situations, and I encourage people to post their experiences.  So thanks for taking the time to test this, and to report extensively on your results.
Title: Re: A new traffic simulator
Post by: RippleJet on October 06, 2008, 05:00:38 AM
The Trip Length To Minutes Multiplier doesn't do anything at all.

Some testing performed last night seems to confirm that! ;)


Simulator Z comes with its own Commute Time Graph exemplar attached (as mott recommended); the Graph Plot Scale property is what actually determines the graph scale.

That's exactly how the RCI graph works as well.
The graph has to be scaled in accordance with the max/min values set in the RCI exemplars.
And there is no information being conveyed from the simulator to the graph about these max/min values.
Title: Re: A new traffic simulator
Post by: b22rian on October 06, 2008, 06:23:55 AM


-Simulator Z does indeed exhibit an additive congestion calculation (Morning+Evening), which I was able to clearly discern with my modified Congestion DataView (attached here, in case anyone wants to try it--it goes down to 25% and uses a really radical color ramp). 



I'll have some hard data to show a bit later.

-Alex (Tarkus)

Thanks a lot Alex for the new congestion data view..
I tried it in my largest city and seems to work great !
.. and also I see you have figured out how to display the reds now also.. &apls

I certainly didnt expect you to do anything with this..any time soon, as I know you are spending just
about all your time with the RHW.. version 21..
So this is greatly appreciated..and a great addition to the game..

Thanks, Brian
Title: Re: A new traffic simulator
Post by: z on October 06, 2008, 01:05:09 PM
Thinking more about Alex's comments, I think I see the solution to the major issues he identified, and possibly the minor ones as well.  The fixes are easy to make; I'll be testing them out on my cities, and if all goes well, I should have an Alpha 2 release later today, or tomorrow at the latest.  So if you're currently running Alpha 1 and it works fine, you can certainly keep running it.  But if you were planning to download it, I'd recommend holding off until Alpha 2.  Also, there's no need to post further results about Alpha 1, as I expect some important behaviors to change significantly with Alpha 2.
Title: Re: A new traffic simulator
Post by: MassHelper on October 06, 2008, 02:50:28 PM
Plz include a readme to help out others

:) Mass
Title: Release of Traffic Simulator Z - Alpha 2 version
Post by: z on October 07, 2008, 02:21:39 AM
At the end of this post, I have attached the Alpha 2 release of Simulator Z.  It contains a short ReadMe file containing the basic information needed to install it.

As promised in my last post, this version contains fixes for the main issues that Alex identiied in his testing.  Specifically, it should now support all forms of RHW.  In the previous version, I had spread out travel paths by lowering the Pathfinding Heuristic.  Unfortunately, as jplumbley mentioned and Alex demonstrated, this is not sufficient to spread out the traffic on the wider RHW's.  The reason for this is clear; the modest speeding premium I gave to uncongested traffic, though realistic, was not sufficient to divert the Sims to the outer lanes.  So for now I am doing what is known to work, and making the highest speeding premium 40%.  Fortunately, increasing the speed values on the high end of the congestion vs. speed curve does not trigger the congestion display bugs.  However, I think that Sims should be warned that if they are going to travel at the higher speeds, they should be sure to get themselves high-quality radar detectors.

When thinking about Alex's finding that Simulator A seemed to allow the commuters to go further into the third and final city tile of the commute in his region, the only thing I could think of as a possible cause for this behavior was the speed premium in the congestion vs. speed curve.  With that premium equalized, it will be interesting to see if that behavior persists.

The only other change I made was a slight decrease in the intersection effect, which Alex noted as congestion at his street intersections.  The congestion will still be there, although it will be somewhat less; it's supposed to be there.  Even in intersections that show up as solid red, in this simulator that simply means that for that one square, traffic speed will be reduced by 70%.  That's far less of a delay than a four-way stop would involve.  It also corresponds roughly to the slowdon a car would experience when making a turn.  Unfortunately, the intersection effect is a very blunt instrument, and cannot be adjusted for different networks or different types of intersections (as our friends on the TLA project know all too well).  I have tried to set this at as realistic a value as I could.  I went through my own cities and found a number of street intersections, and none of them was heavily congested - most were not congested at all.  So I think that input from a number of sources will be necessary to decide what is best here.  Another possibility is to raise the capacity of streets slightly; again, user input will determine whether this is done.

So here's the new version; if you're upgrading from Alpha 1, you simply need to remove the Alpha 1 version and replace it with this one.  And Alex, your feedback was extremely valuable, so if you wouldn't mind running the same tests again, I would appreciate it greatly.  And for everyone else, the more people who download this simulator, try it out, and post their experiences (both good and bad), the better this simulator can be made.

EDIT:  This version of the traffic simulator has been superseded.  You can get the current version here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=4809).
Title: Re: A new traffic simulator
Post by: MassHelper on October 07, 2008, 08:17:22 PM
What are the traffic controller files that are req'd for removal??

P.S. Maybe a cleanitol text file might help out...  :-[

:) Mass
Title: Re: A new traffic simulator
Post by: z on October 07, 2008, 10:00:41 PM
All the traffic simulators start with NetworkAddonMod_Traffic_Plugin, and are usually found in the Network Addon Mod folder.  (Another place to check is the z_CAM folder, if it exists.)  Any such files should be moved out of the Plugins folder tree before installing this simulator.

A Cleanitol file will eventually be included if this simulator is formally released; in alpha releases such as this one, where the installation is fairly simple, they are often skipped.  For example, the alpha releases of Simulator B had neither a ReadMe nor a Cleanitol.
Title: Re: A new traffic simulator
Post by: MassHelper on October 08, 2008, 09:06:05 AM
alright  :-[

:) Mass
Title: Re: A new traffic simulator
Post by: 0rion79 on October 12, 2008, 10:20:23 AM
Z, your traffic simulator is just GREAT!

I have tested it on some of my largest cities and some of them where affected by commuters loop, even if I have built them placing inter-city connections in the middle of city borders to prevent it, factor that, with Simulator B, was useless.

Also, I have seen that now Sims are much more skilled in finding appropriate jobs for their educational and social level: at last $ Sims go working in farms and dirty industry, that before were ignored by them and, especially, when Sims move out from the starting city, it is because they really know where to go working and don't commute as blind beings, without any destination, but go stright to their new working places.

I can say this because I have played again a smaller reproduction of my own city, Cagliari, that is a dense 350.000+ souls formed almost entirely by residential buildings with commercial facilities at ground floor, while all the industry (no matter what kind) is quite far away and often is just in other provinces.
In fact, before it was affected by "lack" of working places even if Raphael version of Census repository was telling me that it was full of vacant jobs. Well, after replacing NAM simulator B, everything flew fine and I have fixed all problems of unemploymend caused by bad inter-city pathfinding! Sims now are employed even into plopable I-M and I-D lots that, before, where ignored.
Instead, in other cities that were really over-populated, I have been able to recognize that jobs were missing and that it was not the inattitude of Sims to find employment.
If you want, you can take a look to that city here: http://www.simtropolis.com/forum/messageview.cfm?catid=36&threadid=93825&highlight_key=y&keyword1=cagliari (http://www.simtropolis.com/forum/messageview.cfm?catid=36&threadid=93825&highlight_key=y&keyword1=cagliari)

Ah, of course I have even seen some backdraw (or positive effect). it depends from the point of view. In one of my cities, I have a ultra-mega-overuse of train stations, that reached 57.000 Sims at once on the same station. I have even downloaded the Simtropolis Train Station that has a capacity of 30.000 passengers, but 57.000 is just too much! But, at last, I don't have over-used rail lines or subway lines. AT LAST!! :)

Instead, about commute time...
Simulator B easy - Simulator Z
City 1 = 85 >> fro 4 to 7
City 2 = 120 >> 6
City 3 = 250+ >> 20+
City 4 = 300+ >> 15
These are all high-density cities on large maps, that works as connection center among several satellite cities and villages on smaller maps.

I know that Z's graphs are made usind different parameters, but still there has been a sensibile improvement in commute speed. Looking from the graphs, it was like if the game has reseted the commuters phat and has begun to calculate them starting over, from the beginning. If the beginning was 0, even the highest scores reached by the graph where not so far away from the starting score and still not so high as the ones with Pathfinder B that I was using before and then, even if I guess that scores among NAM graph and Z graph cannot be compared directly (at least I can't), over all commute time is much shorter and my Sims don't complain anymore about commute times.

Also, I have tried to play on small and middle-size maps, where commute time became 0.6 or even near to 0. It is like if Z graphs shows only effective commute time between a city and another, like if the time needed for Sims to find work in the city where they have both a flat and a work is not considered.

In fact, I did a test with a city of mine called "new Venetia" that is a huge island in the middle of the river, with no bridges. It is self sufficient and commute time was 0. Instead, when I added a ferry, the commute time began to increase to 10, more or less. It looks like that Z mod has even fixed a nasty problem with ferries, where Sims run into them as lemmings and then were moved by sea fluxes instead than actively looking for employment.

Now, a couple of questions.
1 - what is RHW? I have seen it here and there on this post but I don't know the meaning.
2 - in your new congestion & volume view, I have seen that, when I go to see usage, many streets and even highways turns "red" (or deep orange) in the traffic volume view,, even if they are green in the congestion view,. I remember that, in the volume view, there was a note like "*based on street capacity". What does it mean? If I see an highway turning red in the volume view, and NOT in the congestion view, do I have to worry about?

Thank you! And my best compliments again for your great work! I will keep using it!
Title: Re: A new traffic simulator
Post by: MassHelper on October 13, 2008, 07:36:19 PM
RHW = Rural Highway  :-[
As for your second question, my friend, you don't have to worry about the congestion, since they wrote in the Maxis handbook (included with the game) that you can have high volume on a transit path, but you would not have any congestion.
Street cap question...  :-[ not rly sure about that, u might want to ask the transit guru (a.k.a. jplumbley, Jonathan ---> Warrior (Smart kid, :), I know), Alex (Tarkus), or the creator himself (U no who I am talking about... $%Grinno$%))

:) Mass
Title: Re: A new traffic simulator
Post by: z on October 14, 2008, 12:58:24 AM
Z, your traffic simulator is just GREAT!

Glad you like it!  And thanks for the feedback.

Quote
Ah, of course I have even seen some backdraw (or positive effect). it depends from the point of view. In one of my cities, I have a ultra-mega-overuse of train stations, that reached 57.000 Sims at once on the same station. I have even downloaded the Simtropolis Train Station that has a capacity of 30.000 passengers, but 57.000 is just too much! But, at last, I don't have over-used rail lines or subway lines. AT LAST!! :)

You have a couple of options here.  There are some train stations with even bigger capacities; I have an early one from the STEX with a capacity of 50,000.  Even better, just learn the very basics of Ilive's Reader, and then by adjusting the value of Transit Switch Traffic Capacity in the station of your choice, you can set the capacity to whatever you want.

Quote
Instead, about commute time...
Simulator B easy - Simulator Z
City 1 = 85 >> fro 4 to 7
City 2 = 120 >> 6
City 3 = 250+ >> 20+
City 4 = 300+ >> 15
These are all high-density cities on large maps, that works as connection center among several satellite cities and villages on smaller maps.

I know that Z's graphs are made usind different parameters, but still there has been a sensibile improvement in commute speed. Looking from the graphs, it was like if the game has reseted the commuters phat and has begun to calculate them starting over, from the beginning. If the beginning was 0, even the highest scores reached by the graph where not so far away from the starting score and still not so high as the ones with Pathfinder B that I was using before and then, even if I guess that scores among NAM graph and Z graph cannot be compared directly (at least I can't), over all commute time is much shorter and my Sims don't complain anymore about commute times.

Also, I have tried to play on small and middle-size maps, where commute time became 0.6 or even near to 0. It is like if Z graphs shows only effective commute time between a city and another, like if the time needed for Sims to find work in the city where they have both a flat and a work is not considered.

In fact, I did a test with a city of mine called "new Venetia" that is a huge island in the middle of the river, with no bridges. It is self sufficient and commute time was 0. Instead, when I added a ferry, the commute time began to increase to 10, more or less. It looks like that Z mod has even fixed a nasty problem with ferries, where Sims run into them as lemmings and then were moved by sea fluxes instead than actively looking for employment.

Ah, commute time.  As I mentioned in an earlier post, I used mott's formula to set the scale of the commute time graph.  But I saw a post on Simtropolis a while ago that indicated a different way of computing the proper value.  And although the numbers seemed to be right for my large cities, some numbers seemed too low in others.  And then the data you report definitely sounds incorrect.  So I decided to get to the bottom of this; I did an experiment.

I took an unused large city tile, constructed a road exactly 8 km (512 squares) long, zoned a residence at one end and a business at the other, and put in power and water.  I also temporarily modified my simulator to remove the speed premium so that I would be working with a constant, known speed.  Based on a speed of 50 kph for cars, raw commute time should have been 19.2 minutes.  I ran the simulator, quickly got some buildings and commuting Sims, and the commute time quickly went from zero to...  55 seconds!  Way off.  So I figured out what I would have to do to the graph scaling constant to make it come out right, put that number in, and reran the test track.  This time it came out to 19.2 minutes, as expected.

But what about my cities that had looked OK?  Unfortunately, commute times there went up proportionately as well.  The city I had been working with now had an average commute time of twelve hours, which made no sense at all.  Not only was the average commute time higher than the maximum  ???, but a one-way six hour trip on a road would take a Sim roughly 300 km (183 miles).  So something was seriously wrong here.

I thought, Maybe mass transit worked differently?  So I went back to my test track, ripped out the road, replaced it with a train track, put little stations at each end along with road access, and ran the simulator again.  The commute time graph showed perfectly accurate numbers here, shorter than the road numbers by the exact proportion that trains were faster than cars.

So test cases worked with this number, but real cities didn't.  That was really strange.  I started looking at the commute time for my other cities, and a pattern quickly became evident.  The more intercity traffic a city had, the higher the average commute time.  It got to the point where I could predict the average commute time based on my knowledge of what the city's intercity traffic was.  One city that looked very much like my city with a twelve hour commute tiime, but had the least intercity traffic, had a commute time of 70 minutes.

So this is clearly an SC4 bug, because it means there is no value for the Commute Time Graph scaling factor that works in all cities.  In fact, the proper value differs from city to city, or even in the same city at different times, depending on the level of intercity traffic.  This seems connected to my discovery that I had to increase the maximum commute time well beyond what should have been needed in order to generate large volumes of intercity traffic.

So what to do in this situation?  I have decided to make the Commute Time Graph scaling factor half of what my tests say it should be (i.e., .04 instead of .08).  This will increase the commute times you have seen by about a factor of ten, which will be much more reasonable.  It will also eliminate the zero-lenght commute times (which were just commute times under half a minute, rounded down).  For cities with a small amount of intercity traffic, the Commute Time Graph numbers will be approximately correct.  But the bug I found makes it impossible to make them correct in all situations.

As for other simulators, I don't know what the best value for the Commute Time Graph scaling factor whould be; other tests will have to be done for them.

Quote
Now, a couple of questions.
1 - what is RHW? I have seen it here and there on this post but I don't know the meaning.

As MassHelper pointed out, it stands for Rural Highway.  You can find a huge thread about it in the stickies in NAM Creations.

Quote
2 - in your new congestion & volume view, I have seen that, when I go to see usage, many streets and even highways turns "red" (or deep orange) in the traffic volume view,, even if they are green in the congestion view,. I remember that, in the volume view, there was a note like "*based on street capacity". What does it mean? If I see an highway turning red in the volume view, and NOT in the congestion view, do I have to worry about?

In the traffic volume view, unlike the traffic congestion view, there is one scale for all networks displayed.  For each travel type, I picked the network that seemed most appropriate for that travel type's volume.  For example, freight trucks, which usually have a low volume, use street capacity, which is 750 per commute period; this means that you will get red displayed in the freight truck view whenever you have a volume of 2250 (300% of 750) or greater.  However, highways have a capacity of 22,500 per tile per commute period, which means they can turn red if you have just 10% of their capacity used in the freight truck view.  This is unusual, but it can happen.  Such a highway would, of course, show up as green in the congestion view, as it is not congested.  The only time you can use the colors as an indication of congestion is when you are looking at the same network that the travel type is based on, and you are not looking at a view that contains a non-traffic producing travel type (such as buses).  But if you keep this in mind, then, for example, by looking at the Car view, by averaging the colors of the Morning and Evening Commute, you can get a very good idea of what the congestion on a particular road is.  This works in all simulators.

For more information, please see my thread Proposal for a New Traffic Volume View (http://sc4devotion.com/forums/index.php?topic=5409.0).
Title: Re: A new traffic simulator
Post by: 0rion79 on October 14, 2008, 03:10:05 AM
Well, Z, thanks for the hints.
If I can give you my opinion, I think that you should care just about the inter-city commute time. Usually, cities with no connections have no commute problems, so even if your mod makes commute time very close to 0, it would not be a problem anyway. Instead the game suffers a lot when Sims become really outliers and it is here that the biggest differences are seen. It is not a case that the cities with those outstanding commute times where the huge metropolises that had even 8 connections with other 8 neighbour cities and, even if all connections where green and without congestions, it was simply impossible to obtain shorter commute times.

Else, I don't know if the graph shows the highest commute time or just the average commute time BUT if we assume the second one, it is even true that in rural villages (like the ones where I did my tests and had a 0.6 commute time) very often farmers live just adjacent to their farms and so the commute time is less than 1 minute... or, else, we would set that the graph in your mod only indicates the effective commute time needed ONLY by those commuters that work in a different city than then one where they live.

But anyway, if the game is not suffering for single-city commute time but only about inter-city commute time, then just fix the second one and don't care about the first one, even if it would be a bit less realistic. But for me it would be even less realistic to have a map with cities with no connections! :) So I even expect every player to build at least one connection per city, if not more!!!

Ah, may I know what is the set speed for trains, subway, monorail, el.train and ferry in your mod? use Km/h please.

About trains, I just wished to know if it was "normal" that so deep usage in some of my cities. Since I don't think that I will change traffic simulator now that yours is going so fine, may I know what traffic cost do you suggest for:
"non transit-enabled" stops,
bus stops,
monorail stops,
subway stops,
passenger train stops
multi-transit stops (eg_ train+subway or bus+subway)?

What do you think about modding my stops to force the sims to enter only from the entrance and NOT from every side of them?
Thank you!
Title: Re: A new traffic simulator
Post by: z on October 14, 2008, 04:39:07 AM
Well, I will certainly be giving this more thought before I make changes to the commute time scaling.  And I'd be happy to hear from other people about their opinions.  But I should mention that it's not the number of connections to other cities that affects the scaling, it's the volume through those connections.  For example, in my city with the 12-hour commute time, I have hundreds of thousands of Sims commuting to other cities.  It's that number that seems to be associated with the problem, not the number of connections.

As for the meaning of the Commute Time, it's supposed to be an average.

In the end, I think it's useful to repeat something that jplumbley has said many times:  It's not the actual numbers on this graph that are important, but how they change over time.  Clearly, this is made more difficult if the volume of intercity traffic is changing, but that tends to be a long-term process, and the basic principle still applies.

As for the speed of the various travel types, this is all given on the first page of this thread, in the fourth post.  Ferry speeds are not given because they are not controlled by the traffic simulator plug-in, which means they are probably fixed.  If anyone knows what they are, please post.

As for passenger train usage, I have some cities with similar levels of usage.  Since I tried to give real-world values to as many parameters as I could, usage levels such as this are not surprising, since they are common in the real world.

When you are asking for traffic costs for stations, are you actually asking about traffic capacity?  If so, please see the first post in this thread.  As mentioned in the post announcing the Alpha 1 release, I recommend the use of RTMT stations along with the included file in the simulator release; these implement the capacities I recommend, and which have worked well.  For roadside transit stations, I recommend RaphaelNinja's stations, but with doubled capacity.  (You might want to reduce the plop cost on those, as their cost seems to be much higher than similar stations.)

As for modding your stops to force Sims to enter and exit only from one side, I haven't looked into this much personally, but I know that a lot of people recommend it, because it eliminates pedestrians' using the station as a shortcut.
Title: Re: A new traffic simulator
Post by: 0rion79 on October 14, 2008, 06:49:28 AM
Sorry Z, it is my fault: I wished to know how do you suggest to set the tranit switch entry cost. Just to avoid misunderstandment, I mean the value that indicates the time that Sims and/or mass transits vehicles need to cross that mass transit station.
I ask so because in a previous post you have told me that it depends from mass transit speed too! And so, since you have changed some speeds, I would like to know if I should keep my "0,05" value or if I should use something higher or lower.
Thank you! :)
Title: Re: A new traffic simulator
Post by: z on October 14, 2008, 03:11:02 PM
There are two cases here.  If you have a TE lot, with a network running through the lot, the tranit switch entry cost should be the inverse of the predominant travel type's speed.  So, for example, all RTMT stations on roads, where cars travel at 50 kph, have a tranit switch entry cost of .02.  This is a neutral value that neither speeds up nor slows down cars.

For roadside stations, where vehicles cannot travel, the main concern is to prevent pedestrian shortcutting.  This can be done by making the tranit switch entry cost the inverse of the pedestrian speed of 5 kph, or .2.

The Maxis lots, and many independently-developed lots, have a tranit switch entry cost of zero.  This can have amusing results.  For a large TE train station, the Sims can all be observed getting off the train at one end of the station, walking to the other end (since this takes zero time) and then all getting back on the train.  This can be avoided by setting the station's tranit switch entry cost to the inverse of the train speed (200), or .005.

It's important to note that tranit switch entry cost is specified on a per tile basis, so you don't have to multiply any of these numbers by the number of tiles in a particular path.
Title: Re: A new traffic simulator
Post by: MassHelper on October 14, 2008, 03:29:52 PM
As for the traffic simulator files, z, can you plz get the cleanitol file installed in... (Not trying to annoying, but I am anxious (and desperate.. cause of the traffic overflow I am having in my city) to use the new simulator  and don't want to mess up the game or have any CTDs because of not knowing which files to delete)

TY

:) Mass
Title: Re: A new traffic simulator
Post by: 0rion79 on October 15, 2008, 01:49:35 AM
For a large TE train station, the Sims can all be observed getting off the train at one end of the station, walking to the other end (since this takes zero time) and then all getting back on the train.  This can be avoided by setting the station's tranit switch entry cost to the inverse of the train speed (200), or .005.

Z, sorry, are you sure that it is .005 and not 0.05? Coego wrote me so in another thread, but about Maxis & NAM standard speed, that are much slower than yours!

Two questions:
1 - what do you mean by "inverse of the speed"? Using your example, what should it be? 0.002?
2 - can you suggest me any alternative program to edit stosp transit switch point, that is NOT SC4tools? it is has some bugs for me and all those hexadecimal values in other tools are too complicated for me!

Ah, in your traffic simulator, RTMT descriptions do not match with effective capacity: I think that you just didn't care about this side! :)
Title: Re: A new traffic simulator
Post by: z on October 15, 2008, 02:30:47 AM
Since the train speed in my simulator is 200 kph, the inverse of that is 1/200, which does come out to .005.  Now of course if you have a big station where pedestrians can enter and exit from opposite sides, they'll zip through the station at train speed.  Generally, this does not have a big effect on the game.  But if you limit the pedestrian access to one side of the station (such as the front), you eliminate this problem completely.

I prefer Ilive's Reader for editing exemplars.  For properties that are in hexadecimal, you can just type a decimal value in the field, and the program will convert it to hex.  For converting hex to decimal (or back, when necessary), I just use the standard Windows calculator in Scientific mode.

As for RTMT, please understand that it is completely separate from the traffic simulator!  Cogeo chose the current capacities displayed to be network capacities rather than station capacities.  In the next version of RTMT, I am changing that so that the descriptions show station capacities.  This change has already been made; the RTMT file included with the next release of the traffic simulator will have it.
Title: Re: A new traffic simulator
Post by: 0rion79 on October 15, 2008, 02:54:36 AM
Thanks for everything. Of course, I will glady wait for it! :)
Title: Re: A new traffic simulator
Post by: 0rion79 on October 28, 2008, 04:18:19 AM
cars air pollution

Z,

testing your mod in the spare time, I'm registering impressing levels of air/traffic pollution. Avenues and highways are surrounded by a yellow color that is nearby to orange. I have made a test in a city that, before, was working fine and now I have the following scores:

Population 132.000
Average pollution: between 25/30 (and there are no industies or dirty power plants)
Traffic distribution:
pedestrian 100.000
Sub/el: 90.000 (subway and monorail)
Bus: 70.000
Passenger train: 60.000
Cars: 40.000

traffic pollution is becoming really a problem in high density cities, and that one is not even that big. I don't remember such high scores in previously built cities: pollution, yes, but around 15.
If I remember right, you have incresed the % of Sims using cars, to make the game a bit more realistic, and decreased car pollution, right? Maybe this is the cause...

Also, you should see the shape of that city.

It has a more external ring made with highway, then another monorail ring. Then, it has bus&subway stops to "cut" across the city, but Sims, instead than switching from subway to monorail (that are very close) prefer to take the buses. Without buses, the use of subway is drastically limited and reduced even if they occupy the same place.

I would like to ask this: is it possible to set different pollution levels for $,$$ and $$$ sims?
To make a more realistic game, $ sims may have old cars that are cheap to afford but have old, very polluting engines. Or use motor-bikes, that also are not very clean. $$ Sims have cards that are a mid-way, since they are not that rich to afford ecological prototypes but alsto tend to have better and newer cards that produce less pollution because have a better engine tecnology, while $$$ sims have very expensive cars, that are often hibryd or use alternative power sources, like GPL, gas or bio-diesel: being ecologist is cool and in fact even my loved Ferrari does care a lot about CO2 emissions :)
In this way, since $ sims are the ones that most often use mass transit systems, over all traffic air pollution should be a bit easier to keep under controll! Even because, as far as I know, there are no other remedies for traffic air pollution!!
Title: Release of Traffic Simulator Z - Alpha 3 version
Post by: z on October 28, 2008, 08:49:29 PM
At the end of this post, I have attached the Alpha 3 release of Traffic Simulator Z.  It features more realism in the areas of traffic pollution, the Congestion vs. Speed curve, and more realistic numbers for the Commute Time Graph.

testing your mod in the spare time, I'm registering impressing levels of air/traffic pollution. Avenues and highways are surrounded by a yellow color that is nearby to orange. I have made a test in a city that, before, was working fine and now I have the following scores:

Yes, I had noticed this and fixed it in my own version a while ago.  The problem is that I made the fix in the Utilities simulator, which has all sorts of other settings in it, a number of which are affected by some popular game mods.  So this wasn't really suitable for a general release.  Instead, I convened a special session of the SimNation Congressional Parliament (you have to be in God Mode to do this) and had them pass an amendment to the Clean Air Act that greatly limits traffic pollution in those cities where the Act is enabled.  So try it out, and let me know what you think.  Meanwhile, since I was fixing this issue, there were a couple of other fixes that had accumulated that I mentioned at the top of this post, so I have released them all as Simulator Z Alpha 3.

Quote
Also, you should see the shape of that city.

It has a more external ring made with highway, then another monorail ring. Then, it has bus&subway stops to "cut" across the city, but Sims, instead than switching from subway to monorail (that are very close) prefer to take the buses.

This sounds like you've run into the basic limitations of the pathfinder.  If your monorail is in the shape of a ring, then the pathfinder looks at all paths as you cross the ring toward the city center.  It doesn't look at the entirety of the paths, though; it's been shown that the beginning part is the most important.  And when the pathfinder looks at the ring, it sees that at least the first few squares are perpendicular to the direction it wants to go, which means that the distance from the center is actually increasing slightly over those first few squares.  Not only that, but since the monorail is very fast, the pathfinder thinks that that path is moving you away from the center at a high rate of speed.  So it doesn't look very far down that path.  After all, the bus line is headed directly where you want to go, and the pathfinder considers speed only if alternate routes aren't too far apart.  Otherwise, it chooses the shortest distance.  I have the pathfinder set at maximum optimization in Simulator Z, so I don't think this problem can be fixed without access to the underlying code and essentially rewriting the simulator.

Quote
Without buses, the use of monorail is drastically limited and reduced even if they occupy the same place.

I don't really understand this sentence.  Would it be possible to post a picture of this situation?

Quote
I would like to ask this: is it possible to set different pollution levels for $,$$ and $$$ sims?

No, this is not possible.  But I think my modification to the Clean Air Act should solve your problem.

BTW, Orion, I would like to thank you for your extensive feedback on my simulator.  I really need feedback like this in order to know how my simulator functions in a wide variety of cities.  So for other people who have downloaded this simulator, I would really appreciate any feedback you can give, even if it's just to say that everything works fine.  Feedback is especially useful from people who have multiple large cities and significant intercity traffic, as this was the primary situation for which this simulator was designed.  Also, especially for larger cities, I'd appreciate comments on network capacities, such as whether they're too high, too low, or about right.  For smaller cities, I'm mainly interested in how the simulator works in general; if the simulator is formally released, there will be versions available with smaller network capacities.  But to get to that point, I need testing and feedback, so whatever you can tell me will be helpful.

EDIT:  This version of the traffic simulator has been superseded.  You can get the current version here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=4809).
Title: Re: A new traffic simulator
Post by: 0rion79 on October 29, 2008, 12:56:16 AM
My fault: it was a lapsus. I ment that, without bus stops, the use of SUBWAY is reduced. Sims use it less, even if subway stops are just in front of their houses. I would expect them to take subway and reach the nearest stop and then switch to bus, but -without bus stops- they just use car more and - with bus stop - I've seen that they just take the bus to the final destination even if slower, instead than switching from subway to bus.

About air pollution, I will try your mod later and then I'll tell you.
Title: Re: A new traffic simulator
Post by: z on October 29, 2008, 01:28:50 AM
What type of subway stops are you using?  And does this problem happen in the middle of a subway line only, or also where subway lines intersect?
Title: Re: A new traffic simulator
Post by: 0rion79 on October 29, 2008, 04:36:47 AM
Z, don't know what to say: with version 3, the pollution problem is just gone, and there is a much better distribution of subway use, from outside to city center. From the other side, the monorail is basically much LESS used, nearby to 0 (but is still damn cute to see! :D)

It is not very clear for me what you ment with "SimNation Congressional Parliament (you have to be in God Mode to do this)" but I'm using the "improved clean air ordinance" MOD (effect & costs x5) and I've seen that now the cost has passed from the expected 250 to 600+ Simoleons and air pollution is between 15 and 20, and only pale yellow on avenues.

Can you give me more step-to-step options about this  SNCP option in God Mode?

Anyway, I'm using RTMT 3.5 stations.
Title: Re: A new traffic simulator
Post by: z on October 30, 2008, 02:30:10 AM
Z, don't know what to say: with version 3, the pollution problem is just gone, and there is a much better distribution of subway use, from outside to city center. From the other side, the monorail is basically much LESS used, nearby to 0 (but is still damn cute to see! :D)

This all makes sense.  The increased subway use is most likely due to the changes I made to the Congestion vs. Speed curve, which affects even uncongested networks.  Better working subways would then account for the drop in monorail usage.  Since the Sims can move only in the four cardinal directions, diagonal networks don't really exist; they're just a display illusion.  This also means that a network ring is not pi times the diameter of the ring, but instead four times the diameter; a semicircular route is twice as long as a route directly through the center.  So it is not only shorter in distance for the Sims to take the subway across the ring; it is shorter in time as well.  Basically, ring networks don't do well in SC4, except in short arcs, due to the way SC4 was designed.  You might get more traffic on your monorail if you put in more stations, but you're still not going to get a lot of through traffic.

Quote
It is not very clear for me what you ment with "SimNation Congressional Parliament (you have to be in God Mode to do this)"...  Can you give me more step-to-step options about this  SNCP option in God Mode?

Well, first you click on the...  No!  :'(  I can't do this!  :'(  It was just a joke.  ;D

Quote
I'm using the "improved clean air ordinance" MOD...

Not any more! $%Grinno$%  The amended clean air act included with the simulator has overridden your mod.

Quote
(effect & costs x5) and I've seen that now the cost has passed from the expected 250 to 600+ Simoleons and air pollution is between 15 and 20, and only pale yellow on avenues

This is a very old, antediluvian, pre-Rush Hour mod.  It appears that the clean air act was strengthened for RH from 5% to 10%, so this mod now gives you 2.5 times the effects of the standard ordinance.  It appears to have a fixed cost of §250, unlike standard ordinances, whose cost vary according to population.  Being such an old mod, it was installed with the rpatch utility, which is no longer available, and for good reason:  It actually patched SimCity_1.dat instead of creating a copy of the exemplar that was to be modified.  This is generally considered a Very Bad Thing.  I have gone by the description of what this mod's ReadMe says it does, and I have created a standard .dat file with the resulting mod; this file also has the same reduction on traffic air pollution as the main simulator file.  I've attached the file at the end of this post.  Try it out and let me know if it does what your old mod did; also let me know if you think it's still a worthwhile mod.  You need to put this in your top-level Plugins folder for it to override the simulator copy.

The pale yellow on avenues means that the traffic pollution mod is working as it should.
Title: Re: A new traffic simulator
Post by: 0rion79 on October 30, 2008, 09:05:24 AM
In my cities, I usually give the "illusion" of rings and diagonals, and my monorail rings are just "squares" that have rounded corners, since monorail cannot have perpendicular intersections or bends, as streets or avenues, and there are no "diagonal" stops.
Even so, I have a much lower use of it even if it should be much faster than buses (250 km/h, right?). I expected that the gain obtained by speed should overcome the disadvantages from longer routes but my experiments, with your mod Sims just like it less and will use it only if there are no other opportunities.

Even more, Sims don't "switch" well from stops of different kinds. I have made one of my cities to have another monorail "square" around it, where Sims could switch from Monorail, that makes a "round" around the city center, and then take the bus that has stops that are just adjacent to . I have made some experiments, forcing sims to use only monorail and then switch off and take a bus from adjacent squares, to reach the most far away corners that the monorail doesn't touch, but Sims just don't do it.

As result, while other mass transit systems are nice and useful, the monorail now is useless: encumbering as a train, but with a very low usage.

Anyway, about your ordinance... yes, it is working fine, but I would like to know "how". Does the new Clean Air ordinance affect cars AND industry pollution? And why haven't you used the stantard "Automobile emission reductant act"? I think that the concept behind is working really fine, but you should care about the substance and the form of your idea. Just some new in-game ordinance explanation would help to make the player to "see" that it has a new use.
Title: Re: A new traffic simulator
Post by: z on October 31, 2008, 05:45:16 AM
After looking into this situation extensively, I can say that there is definitely a problem with the use of monorails under Simulator Z.  This problem exists to a lesser extent in other simulators, and appears to be at least partially related to the Pathfinding Heuristic.  Setting this property to a lower value is supposed to improve pathfinding in general, and it does for all other networks, but for some reason, it makes monorail usage worse.  There also seems to be an SC4 bug in that monorail usage can be reported as nonzero in the traffic graph, yet the query tool reports zero usage along the entire length of the monorail track.  I will make it a high priority to figure out what's going on here.  And any further data from you on this (including pictures) would be appreciated.

As for the ordinances, I'll reply to those questions in a later message.  But I do have a very good reason for not using the Automobile Emission Reduction Act.
Title: Re: A new traffic simulator
Post by: 0rion79 on October 31, 2008, 12:36:00 PM
Hi Z, here are some images that hope will help you.
Here is some more data related to the same city, Goldshares (from golden plowshares)

Population: 109.000
Mass transit usage:
pedestrian 90.000
Subway and bus: 70.000
Cars: 50.000
Passenger train: 20.000
Monoral: 1.400

R§§§ 70.000
R§§ 35.000
R§ 4.000 (no cheats, really!)

This is a snapshot of the city from above: (http://farm4.static.flickr.com/3230/2988896079_69741ab40a.jpg?v=0)
This is the city zone view, so that you can see the monorail: (http://farm4.static.flickr.com/3169/2988896407_6975f2a2a4.jpg?v=0)
As you can see, subway is perpendicularo to the main avenues: (http://farm4.static.flickr.com/3211/2988896635_6c251270ce.jpg?v=0)
And this is a concentration view of air pollution: (http://farm4.static.flickr.com/3026/2988895691_1b1fff6a83.jpg?v=0)

I have to say that, even if I don't see any difference with your "Super Clean Air Act" installed in "plugin folder" if compared with the one already included in your traffic simulator ver.3, It is possible to use PEG artificial trees or natural trees and parks to lower air pollution.
Here is the Air Pollution scores:
With PEG trees inside city area and all ordinances ON: 8
Without PEG trees: 14 (as in the picture)
With "cars pollution reductant ord." OFF: 16
With your Super Clean Air ordinance OFF: 24
Note also that I have reduced subway stops in residential areas because I wished to promote the use of monorail, but without success and that the other only polluting source is a Small international Airport, and that the map size is medium.

In another city, I have obtained the scores of Air Pollution = 70, but it is part of a "project" of mine, where I've built a "large" city using 9 small adjacent maps, with some problem of commuters loop (of course!) and where there is a huge in&out flux of cars and buses, and there is not much space for trees and parks, so it is ok to have the city so dirty.

If you need other informations, please ask.
Title: Test of "Z" traffic sim
Post by: b22rian on October 31, 2008, 06:47:31 PM
Hi Steve..

i finally got around to installing your updated traffic sim Z.. in my million population city and I thought it would
be interesting to look at some test results versus the previous traffic sim I had installed which had been
Mott's traffic sim B " hard difficulty.. What I did was quite simple.. I let the game run for a 5 year period without
making any further developmental changes to the city.. and here are my findings on traffic usages :

   Current traffic usages using Traffic Sim B  ( hard difficulty)...

Date   ...   5- 25- 435
Population ..  1091 K

          TRAFFIC  USAGE  ...

Pedestrian..          400 K
Car         ..          250 K
Sub/ El / GLR  ..    240 K
Bus       ..            185 K
monorail ..            170 K
train     ..             145 K 


    Test traffic usages... ( 5 year test period)  Traffic Sim  " Z"...

Date    ..  5 -25- 440

         TRAFFIC  USAGE  ...      Difference from Traffic  Sim B  ...    % change...

Population..    1126 K                             ( + 35 K )                      ( 1.0 % )

Car         ..         390 K                         ( + 140 K )                    ( + 64.1 % )
Pedestrian..         295 K                         ( - 105 K )                    ( - 26.3  % )
Subway/ El/ GLR.. 150 K                         ( -   90 K )                    ( - 37.5  % )
Train        ..        148 K                         ( +    3 K )                     ( +  2.0  % )
Bus          ..        82 K                           ( - 103 K )                     ( - 55.7 % )
Monorail    ..        75 K                          ( -  95 K )                      ( - 55.9 % )

Here are some percentage comparison  traffic usages  of the  2 traffic sim's.....
percentages as  a function of total traffic usage is in the brackets below ...

   ***   also please note , that total traffic usages will exceed the population figures because of some sims
            taking multiple forms of transportation on a single trip...

   Traffic comparison          ... Pedestrian       VS.         Car        VS           Mass transit....
 
Traffic Sim  B (hard)          400 K   ( 28.8 % )               250 K   ( 18.0 %)              740 K  ( 53.2 %)

Traffic Sim  "z"                  295 K   ( 25.9 %)                390 K   ( 34.2 %)              455 K  ( 39.9 %)



    Traffic  Comparison ......       CAR              VS.                   Mass  Transit ...

Traffic Sim B (hard)            250 K   ( 25.3 %  )                            740 K  ( 74.7 % )

traffic Sim  " z "                 390 K    ( 46.2 % )                             455 K  ( 53. 8 %)


.. .  and finally a chart showing the different modes of mass transit as a function of total mass transit usage
      and how the 2 traffic sim's compare.. ON A PERCENTAGES BASIS..


MASS  TRANSIT  MODES..   Sim B % usage...   Sim " Z"  % usage...   comparison...

Subway/ el/ GLR                  ( 32.4 % )               ( 33.0 % )               ( + 0.6 % )
Bus                                   ( 25.0 % )              ( 18.0 % )               ( - 7.0  % )
Monorail                             ( 23.0 % )               ( 16.5 % )               ( - 6.5 % )
Train                                 ( 19.6 % )               (  32.5 % )               ( + 12.9 % )


...   other comments and observations...

***   I read the above threads on the monorail usage  issues .. Although there was slight drop in
       monorail usage.. using the Z traffic sim..  but it was'nt an appreciable difference - 6.5 % as a function
       of total MT..

***  I am more a MT guy i suppose, ..i do realize many others are more road and hwy guys and gals..
       Which may explain the high numbers of MT in this city..

*** The obvious thing that the z traffic sim does as compared to the nam ones is increase the use of
       cars over MT, which steve designed it to do... and i also agree a more realistic reflection of real
      life traffic, if that is what you are looking for in your games..

***  Its possible there is less mass transit switching going on and less multiple modes of transport on single
       trips using the Z sim.. although cannot confirm this for sure from the data..

anyways i hope all this data helps some decide which traffic sim is best for them.. according to what your
looking for with your traffic goals and plans.. It is by no means some comparison saying one is better than the
other nor is it meant to encourage the use of one over the other.. hopefully just useful data for a few people..

really there are enough difference i think between the 2 .. that you could end up playing 2 diverse cities in terms of transport goals and plans..If you look at it in that light, it would add more enjoyment and diversity to an already fun game.



Regards, Brian

Title: Re: A new traffic simulator
Post by: MassHelper on October 31, 2008, 07:41:47 PM
Brian... do u know which files to remove from NAM (Apr. 2008) in order to use Simulator Z...

Note: Can u list the files?


:) Mass
Title: Re: A new traffic simulator
Post by: b22rian on October 31, 2008, 08:20:01 PM
Brian... do u know which files to remove from NAM (Apr. 2008) in order to use Simulator Z...

Note: Can u list the files?


:) Mass

sure..  here are the files you want to remove from your nam folders.. (Make sure u check both you my docs nam folder and the
maxis plug in folder just to be sure.. i had a duplicate file of one of the volume views in there although the
majority of my nam files are in the my docs plug in folder).. any files starting with...

networkaddonmod_traffic plug in......

also remove the network add on volume data view files

and also i think the congestion view files..

although i was a little unsure about needing to take out tarkus.s new congestion  view a002 ( which by the way
if havent used it yet is a beautiful creation !)
I took it out anyways just to be on the safe side..

than in their place you will want to put in your nam folder his nam traffic plug in file  " Z " and his volume view file
( he also provided a RTMT file if you are using that , which increases station capacities a bit)

also I wanted to mention something that i neglected in my above testing post...
I had to allow over 2 years (believe it or not !) before i started seeing changes in my traffic graphs !..
It may have had something to do with the complexity of my traffic systems and size of my city I
tested it in ( over a million population).. but you definitely have to give it quite a bit of time to make the
adjustments in a gaming sense..

Hope this helps, Brian

***  Edit.. he also provided a read me file in his zip which explains which files to remove and add..
Title: Re: A new traffic simulator
Post by: MassHelper on November 04, 2008, 06:22:49 PM
I do hope that your list of files would not cause my PC to have CTDs

Note: I really need this simulator because my city took around 10 years to grow from 1930K to 1935K people and my streets (literally) are loaded with cars.

With all due respect, thank you.

:) Mass
Title: Re: A new traffic simulator
Post by: MassHelper on November 04, 2008, 09:02:53 PM
50% (or more) of my population uses mass transit and the problem is the capacity. Recently, I used SC4 Tool to help edit the traffic capacity of rail stations because they are all maxing out... (soon or later, I am gonna have to edit the capacity of subway and bus stations...)

:) Mass
Title: Re: A new traffic simulator
Post by: 0rion79 on November 05, 2008, 12:48:12 AM
I absolutely agree. There is more than one answer to the problem and, as player and user, I'm happier since I can choose.

@Z, about your version 4.0, please warn me when it's out, so I will test it with my cities with monorail.
Title: Re: A new traffic simulator
Post by: MassHelper on November 05, 2008, 06:45:30 AM
Z, can you please include the cleanitol file in Alpha 4?

Thank you for your response!

:) Mass
Title: Re: A new traffic simulator
Post by: z on November 05, 2008, 07:29:28 PM
50% (or more) of my population uses mass transit and the problem is the capacity. Recently, I used SC4 Tool to help edit the traffic capacity of rail stations because they are all maxing out... (soon or later, I am gonna have to edit the capacity of subway and bus stations...)

For bus and subway stations, I would recommend using RTMT with the CAM capacity settings.  They have many advantages over the in-game stations, as well as having much higher capacity.
Title: Re: A new traffic simulator
Post by: b22rian on November 05, 2008, 08:31:15 PM
I wanted to take some time to comment on something I havent seen commented on ...concerning the
traffic plug ins..

But quite soon RHW version 21 is coming out and eventually so is the network widening modules...
Now there is going to be for sure 6 and 8 lane highways... and if your someone who enjoys seeing these
huge super highways put to use.. you may want to think of trying out traffic sim Z.. as according to my
test results , it does seem to encourage more sims to ride cars and use roads and highways , more so than
do traffic sims A and B.. And again im not saying which traffic sim is better...than which , but i think its fair
to point this out.. Also since the future of our game concerning custom transit content does seem to favor
wider transit networks and higher road capacities as well as the advent of these  "super - highways" and you
are someone who actually wants to see these highways used and not just "eye candy".. in some ways I
think traffic plug Z does lean a bit more in that direction ,if your more a highway man... than mass transit guy
..given it puts a bit more preference on sims using cars than mass transit...
Conversely , Sim A and B encourage a bit more use of mass transit over the use of cars...

obviously, you still have the option of simply building larger cities and higher populations.. as well as simply
designing your traffic system for whatever your prioroties are..  and eventually your going to fill up those big
highways and wider networks,,,

But also keep in mind game lag and your pc's
ability to handle huge cities and its subsequent performance..

Brian
Title: Re: A new traffic simulator
Post by: j-dub on November 05, 2008, 10:19:39 PM
I can confirm the mistake Chicaoland made in 2007. I think what he said is the reason the American housing marked collapsed. These new suburbs would be out in the middle of no where, with no amenities around. Its bad enough most roads are 25mph, but you have to drive past hundreds if not thousands of houses before gettting to the main road. These cities all made the mistake of planning too big. These builders didn't want to be around competition, and there would be no commercial near by. And when there was commercial built, majority was empty. The places that did do well were near the rest of civilization, maybe not right there, but close enough. I think the reality of this and the game is if you try to develop too big, it will cause some problems. I learned that from experience. Also having a highway after a certain reach, seems to be my best option for handling thousands of commuters from all these towering infernos.
Title: Re: A new traffic simulator
Post by: b22rian on November 05, 2008, 11:05:23 PM
I wanted to make a few further comments on "realism" with the traffic plug ins and what they mean to me...

In general I agree with "z"'s statement that his traffic plug  does seem to to mirror some of the current larger
american cities  like chicago... where as the reality is they use more cars than mass transit...

If your idea of "realism" is more toward "idealism"  meaning what should we be striving for  in terms of our
increased usage of mass transit and what city planners should be up to  ? In terms of transit goals in larger cities
than i think sim's A and B do this very well.. And also , and  (Jp can speak this this better than I can) The A and B
sim's may actually show a better realistic representation of what goes on in larger european cities, which as I
understand it to be a bit more conscious of using mass transit than their american counter part larger cities..
use their cars and highways more..

In the end though this is still a game.. and you still have to fit your traffic system into whatever traffic mods..
you chose to installl.. So like i said before if its RHW version 21 with 6 and 8 lane super highways  andyou want to
pack with tons of traffic  ? Than sim Z is going to force more traffic on to thoie roads. with all other factors being
equal.. if your goals are for a more elaborate and sophisticated mass transit system in your city , than i think
sims' A and B are going to give you more mass transit usage.. my test results show this to be true..

but isnt  itgreat we have all these wonderful options... ?  ;D

Thank you Z, Mott and J Plumbley

Brian
Title: Release of Traffic Simulator Z - Alpha 4 version (Special Mass Transit edition)
Post by: z on November 07, 2008, 02:24:05 AM
The Alpha 4 release is a major improvement on previous releases of Simulator Z.  The main changes are as follows:

Much improved support for monorails.  After receiving Orion79's bug report about low monorail usage, I discovered that there were many properties in the simulator that affected monorail usage that by all rights shouldn't, and that didn't affect any other form of transport.  By adjusting these properties to various extents, I was able to take monorail usage that was almost nonexistent in my cities and raise it typically into the thousands.  Comparing it against Simulator B, I found Simulator Z's monorail usage to be significantly higher in every case, sometimes by a factor of 100 or more.

Overall improved simulator performance.  The changes needed to fix the monorail bug serendipitously made the whole simulator run better.  (Thanks, Orion!)  Average commute time declined, and many of the data graphs showed a small but noticeable improvement.  Sims had an easier time finding jobs; pathfinding was effectively working better.  Traffic and congestion on all networks decreased.

Support for even more cars.  I tweaked the distribution between cars and mass transit to favor cars a little more, without increasing any road capacities.  The last time I had tried this, problems with traffic and pathfinding started to develop.  But this time, after the improvements described in the previous paragraph, everything went fine.  (Note:  According to many sources, including some quoted by jplumbley, 88% of commuting in the U.S. is done by car, with just 5% overall by mass transit.  In Europe, the car figure is 78%, but is quickly approaching the U.S. figure.  But mass transit lovers, fear not!  There's a bonus for you below.)

Buses now contribute to traffic just like other vehicles.  This is a bit of a tough one, because as jplumbley noted, SC4 buses don't act like real buses at all.  A good analogy would be that every bus stop has a pool of single-passenger motorcycles, and a Sim can get on one and ride it on any route he or she wants as long as the Sim leaves it at another bus stop.  So that's nothing like a real bus, but it certainly is traffic.  And as jplumbley noted, a "busfull" of passengers in SC4 would cause much more traffic than a real life bus.  I tried making making buses contribute to traffic a while ago, and it turned into a mess; the roads got way too clogged.  But once I saw how much better the A4 simulator was working, I gave it another shot.  This time it worked great!  The simulator was much better about routing cars and buses so they didn't get in each other's way, and it wasn't even necessary to raise road capacities, even though bus traffic tends to be greater than car traffic.

As for the fact that SC4's definition of "bus" is unrealistic, the same is certainly true of its trains, which like everything else in SC4, are actually simulated as single-passenger vehicles.  Yet the game's default is to count train traffic.  My change to buses now simply completes the counting of all vehicles as traffic.  But getting this to work without raising network capacities was not easy.

More realistic subway costs.  Subways are ridiculously underpriced in SC4; if they were that cheap in the real world, most cities would have subway networks like Manhattan's.  Unfortunately, it does not appear to be possible to change the cost of a subway tile, as it appears to be hardwired in the executable.  However, the monthly cost per tile can be changed.  So think of it this way:  SC4 subways are paid for by bonds, and interest has to be paid on them every month.  They're interest-only bonds, so they have to be paid forever.  However, demolishing a subway tile obviously removes its monthly cost; perhaps someone can figure out a good cover story for that.

I think that at one point, I figured that to be accurate, subway costs should be increased by a factor of 50.  But I can't just do that in this simulator, as I'd bankrupt a lot of cities quickly.  So I increased the monthly cost by a factor of four.  This is just enough to discourage laying subway lines all over the place, but you can still do that if you have lots of simoleans.  This fits in with the other changes in this simulator; mass transit in general works much better, so lots of subways are not really necessary (though you can still build them if you want).

More accurate numbers for the Commute Time Graph.  This simply refers to the numbers on the side of the graph.  As discussed earlier in this thread, it's impossible to make them accurate for all cities, but the new numbers should be more accurate for most cities.  The shape of the graph, which is the most important thing about it, is unchanged.

All the rail capacities have been lowered slightly.  These were formerly set at 80,000; they are now set at 62,500.  There seemed to be sufficient headroom to make this drop; please let me know how this works out.

A mass transit version of the simulator.  More cars may be more realistic for most cities, but not all (as jplumbley will not let me forget  $%Grinno$%), so I've included a version of the simulator that uses the original distribution of cars and mass transit, which is also in use in Simulators A and B.  Road capacities are about the same as the Easy version of Simulators A and B, although street capacities are equivalent to the Hard version, and highway capacities are higher, for reasons of realism described earlier in this thread.  Other than these differences, the two versions of Simulator Z are identical.  And although the road capacities of the mass transit version are similar to Simulators A and B, the behavior of the simulator as a whole is very different, and is basically the same as the standard version.  Installation instructions are in the ReadMe.

There is now a Cleanitol file for everything.  This was not in the original plans for the alpha version, but someone just kept asking for it...  In any case, please remember that this is an alpha release, and you should know what you're doing if you're going to use it.

Finally, I fixed a problem with the integration of this simulator with existing Clean Air Act mods; details are in the ReadMe.

So that's it for now.  I'm quite pleased as to how this simulator is working out, and I hope to go into beta testing soon - maybe even next release, if this one works out well.  In the mean time, please try this one out and post feedback.  Thanks!

EDIT:  This version of the traffic simulator has been superseded.  You can get the current version here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=4809).
Title: Re: A new traffic simulator
Post by: RippleJet on November 07, 2008, 04:08:59 AM
Unfortunately, it does not appear to be possible to change the cost of a subway tile, as it appears to be hardwired in the executable.

The subway laying cost is given by the property Simolean Cost Per Tile in the MiscNetwork exemplar Subway Placement Tuning Parameters (TGI 0x6534284A, 0x084344E0, 0x0A367CA7).

It comes with a value of §150.
Title: Re: A new traffic simulator
Post by: z on November 07, 2008, 04:49:55 AM
Ah... I was looking under Plop Cost in Subways under Misc Catalog.  But of course that's just the catalog cost!  No wonder it didn't work.

But I'm thinking that I might want to stick with adjusting the monthly cost, which is right in the Traffic Simulator exemplar, as otherwise I'd have to copy the whole Subway Placement Tuning Parameters exemplar, and there seems to be plenty in there that could conflict with various mods.  Any opinions on this?
Title: Re: A new traffic simulator
Post by: 0rion79 on November 07, 2008, 06:21:35 AM
Object - Monorail usage with Z's Alpha 4th

Z, I have tested the same city, Goldshares, from which I've posted the images and I've seen a drastical increasing of monorail usage. At last, I have been forced to use stations with a capacity greater than 5.000 and even in the normal lines, I've seen an increment from 6% (the previous value) even to 98% (2000 passengers).
Still, I have also been able to see that Sims like more the subway.

If mathematic is not an opinion, we know that subway trains goes up to 150 km/h in your mod, while monorail up to 250 km/h, so it is MUCH faster than subway and still Sims like subway more.

Even if the improvement is great, I think that there is still something "wrong", even if I want to test monorail in another city of mine with a different shape, due to a possible bias.
Since being a psychologist makes me a scientis too, I want to make some experiments to verify my opinions :)

The reason for which I believe that Goldshares may lead to a bias is that, even if the monorail goes parallel to subway and so the path length should be more or less the same, shops and offices are only in the city center, while on the outside of the city there are only rewards and civic facilities as chools and hospitals, that simply employ much less people than commercial offices and services.
For this reason, the Sims in my city have much less reasons to use monorail than subway, while in my next city, that is a "fixing" of a previous one that I've called Metropolis Alpha, I've still used the shape of the ring but in the inner part there are residents, while in the outer part of the ring there are high-density offices, so now monorail should really have a meaning for being used.

If something else comes up, please tell me what you think. In the meantime, I want to make another experiment, but I will tell you later. In the mean time, please give me your opinion about my hypothesis. C u!

---------
EDIT
--------

I have made my experiment.
I have modified another city of mine that was merely used to test my modified train stations where I modified the transit switch points to prevent pedestrians from using them as shortcuts.
This time, I did as following: I've built no road from residential to industrial area, forcing all sims to use mass transit and filling the residential and industrial areas with busses, to allow Sims to reach their working places without walking too much.
Note that the residential areas are zoned symmetricaly so that it has been possible to build a rail line, an underground line and a monorail line each adjacent each other, in the middle of the city, preventing bias from residents' position or different zone density.
Then, I've tested the effects with and without a parking garage nearby to monorail station.

So, these are the results:
         with PG      Without PG
Train:     2               163
Subway: 15              34
Monorail: 252            179

As you can see, the monorail is now recognized as the fastest way to reach the working place and wealthy Sims that want to use the car will choose the train, that is a bit slower than the monorail, only because very often train stations have an included parking garage.
I also have tried to built first a street and then a road and then an avenue that links the residential area to the industrial one and there has been no significant change, except that some Sims (60) has begun to drive directly to work when a road has been built, but I'm using Z's mod (the one that DOES NOT end with MT).

Instead, there has been a radical change when I have upgraded the avenue with the highway: then everybody has begun to drive and/or take buss to work, using the avenue and ignoring the other mass transit systems.

Z, this is a bit strange, don't you think? Monorail should still be faster than highway but maybe the last trait, when Sims are forced to drop off the monorail and use the bus to reach their true destination, has a strong influence on the commute strategy, even because I've placed bus stop directly in front of each terminal, to prevent biases due to too long walking trips.

I think that, *if* you have forced busses to move at 15 km/h in streets (maybe I remember wrong), this is having a too heavy impact on busses usage. IMHO, a speed from 25 to 35 km/h would fit much better and still be realistic.

As other news, I'm having congestion problems with avenue roundabouts. Is it normal? Is there any way to increase their capacity?
I have had to drastically increase Morifari's bus blockers and truck blockers too, that I use a lot in my cities to regulate traffic.
Title: Re: A new traffic simulator
Post by: MassHelper on November 07, 2008, 08:49:01 AM
Z, you put the cleanitol file for this one (Yay!)...

With all due respect, Z, thank you

:) Mass

Note: What if we have the Census Repository Building #3? Because the file depends on the Simulator A of the NAM..... (I hope I don't have to destroy it..) One last thing, would it be possible if you can post the new capacities for the transit paths....?
Title: Re: A new traffic simulator
Post by: RippleJet on November 07, 2008, 09:55:16 AM
Note: What if we have the Census Repository Building #3? Because the file depends on the Simulator A of the NAM..... (I hope I don't have to destroy it..)

No, we can't have you destroy it... $%Grinno$%

Enclosed is a zip file with two new versions of the Census Repository Facility, Version 3.
You need to manually replace the one in your plugins folder with the appropriate one.
And you will probably have to replop it, for the transit capacity to upgrade.


Name of the fileCompatible with Traffic Plugins
 
RW_3x1_Census Repository Facility_6000.SC4LotNetworkAddonMod_Traffic_Plugin_Z_MT.dat
 
RW_3x1_Census Repository Facility_12000.SC4Lot    NetworkAddonMod_Traffic_Plugin_Z.dat
Title: Re: A new traffic simulator
Post by: 0rion79 on November 07, 2008, 10:17:51 AM
Too complicated. I have built it in almost all of my cities and don't want to change it.
Also, I've seen that now ti is bigger than 1x1, and instead I like it that small.... :p
Title: Re: A new traffic simulator
Post by: MassHelper on November 07, 2008, 11:25:11 AM
Thanks Tage.... ;)

:) Mass
Title: Re: A new traffic simulator
Post by: MassHelper on November 07, 2008, 02:48:49 PM
For bus and subway stations, I would recommend using RTMT with the CAM capacity settings.  They have many advantages over the in-game stations, as well as having much higher capacity.

What he said, and has said before, is "What was required in that scenario was mixing Residential and Commercial towers to promote people walking to work..."  This is fine if this is what you want to do, and yes, it will allow Simulators A and B to support cities with very high populations.  But most large cities (e.g., Chicago) are not built this way; a common model is to have a large downtown area surrounded by residential areas, many of which are a large distance away and have long commutes.  It was for these common situations that Simulator Z was built.

BTW, Z, do u mean promote walking (and this is not good if it's mixed with NAM Simulators, is it?) as in the option that can be installed along with CAM?
Title: Re: A new traffic simulator
Post by: z on November 07, 2008, 03:05:01 PM
BTW, Z, do u mean promote walking (and this is not good if it's mixed with NAM Simulators, is it?) as in the option that can be installed along with CAM?

"Promote walking" is part of one of the CAM simulators, which should not be installed along with Simulator Z or any of the NAM simulators.  I'll have to add them to the Cleanitol list.  Meanwhile, since you've been able to run Simulators A and B, this would mean you don't have any of the CAM simulators installed, as they override the ones in the main NAM folder due to their location.
Title: Re: A new traffic simulator
Post by: MassHelper on November 07, 2008, 04:32:17 PM
Of course.... but you previously mentioned about adding promote walking in order to use NAM simulator A right.....

:) Mass
Title: Re: A new traffic simulator
Post by: z on November 12, 2008, 12:09:56 AM
Object - Monorail usage with Z's Alpha 4th

I also have tried to built first a street and then a road and then an avenue that links the residential area to the industrial one and there has been no significant change, except that some Sims (60) has begun to drive directly to work when a road has been built, but I'm using Z's mod (the one that DOES NOT end with MT).

Instead, there has been a radical change when I have upgraded the avenue with the highway: then everybody has begun to drive and/or take buss to work, using the avenue and ignoring the other mass transit systems.

Z, this is a bit strange, don't you think? Monorail should still be faster than highway but maybe the last trait, when Sims are forced to drop off the monorail and use the bus to reach their true destination, has a strong influence on the commute strategy, even because I've placed bus stop directly in front of each terminal, to prevent biases due to too long walking trips.

Do you still have a parking garage at the origin of the monorail?

In general, this behavior isn't too surprising, as in this simulator, as in real life, there is a heavy bias toward driving.  The avenue was so much slower than the monorail that the Sims gladly took the monorail instead.  But when you upgraded to a highway, the speed difference was much less, and the Sims couldn't resist the pull of the open road.  Also, transferring to and from the monorail takes time, and then there's the bus at at least one end.  The next version of the simulator makes the Sims more sensitive to time differences in paths, so this behavior should be less dramatic.  Also, I think that if you made your transportation corridor longer, at some point you would start to see Sims deserting the highway and moving back to the monorail.  Finally, if you want, I could tell a little bit more if you posted some pictures of your setup.

EDIT:  I just went back and did the math here, and it looks like the Sims are probably taking the shortest route after all.  In Simulator Z, a monorail takes about one minute to cross a large tile; a car on a highway takes a little over two minutes.  So that's basically a one-minute difference.  But if your travel corridor is, say, a quarter of a large tile (64 squares), then the difference comes down to 15 seconds.  Now even if your Sims park at a garage right next to the monorail, they're typically going to have to walk a couple of squares or so to get into the monorail station, and that takes up a number of seconds right there.  Going from the monorail station to the bus station at the other end takes some more seconds, even if the bus stop is right at the door.  And then at the conclusion of their trip, the Sims typically have to walk a number of squares from the bus stop to their job; many more seconds are used there.  So soon that 15 second advantage becomes a deficit, and the Sims are better off taking the highway.

As for the buses on the highway, some Sims don't own cars, or don't like to use them, so they're going to take rapid transit.  Taking the bus on the highway saves precious seconds transfering to and from the monorail station.  Whether it's actually faster, it's hard to say; throughout this whole process, I've discovered that monorails are just plain weird.  I know how to double their usage in cities by changing a single property in the simulator, but that makes the simulator not work properly with RHW-8's, so I can't do it.  Meanwhile, subways aren't much faster than highways, so when you take access and transfer time into account, they're slower.

But notice what happens when you had an avenue present before the highway.  The 15 second difference (in this example) becomes closer to 45 seconds, which gives the Sims plenty of time to do their transfers, and so they take the monorail in this situation.

Quote
I think that, *if* you have forced busses to move at 15 km/h in streets (maybe I remember wrong), this is having a too heavy impact on busses usage. IMHO, a speed from 25 to 35 km/h would fit much better and still be realistic.

Yes, they are at 15 kph (which is three times their speed in Simulator B); this is to discourage buses from using streets in residential neighborhoods as main routes.  Generally, there should be enough roads in a neighborhood that streets don't need to be used much by buses.  Again, pictures of your setup would help.  I'd also be interested in hearing from other people about what they think about the issue of buses and streets.

EDIT:  Given what I said in my previous edit, I don't think this is your problem.

Quote
As other news, I'm having congestion problems with avenue roundabouts. Is it normal? Is there any way to increase their capacity?
I have had to drastically increase Morifari's bus blockers and truck blockers too, that I use a lot in my cities to regulate traffic.

I don't use roundabouts a lot, but I haven't seen unusual congestion around the ones I do use.  Avenue roundabouts have the same capacity as avenues, and this can't be increased withouth increasing the capacity of all types of roads.  Once again, a picture of the area would be very helpful, especially a congestion view.  Or if you could tell me how many and what kind of roads are going into the roundabout, and what their traffic volume is, that would help some.  A combination of these two would be the most helpful.

The next version of the simulator (which I'm currently working on) is really good at clearing up congestion by rerouting Sims, so that may help you here.  Even the version you have should do that much better than earlier versions; try letting the game run for a while and see if that helps.

EDIT:  The next version of the simulator also specifically has an adjustment for avenues to lower their congestion; in my testing, this is working well.
Title: Re: A new traffic simulator
Post by: b22rian on November 12, 2008, 06:06:56 AM
Do you still have a parking garage at the origin of the monorail?

In general, this behavior isn't too surprising, as in this simulator, as in real life, there is a heavy bias toward driving.  The avenue was so much slower than the monorail that the Sims gladly took the monorail instead.  But when you upgraded to a highway, the speed difference was much less, and the Sims couldn't resist the pull of the open road.  Also, transferring to and from the monorail takes time, and then there's the bus at at least one end.  The next version of the simulator makes the Sims more sensitive to time differences in paths, so this behavior should be less dramatic.  Also, I think that if you made your transportation corridor longer, at some point you would start to see Sims deserting the highway and moving back to the monorail.  Finally, if you want, I could tell a little bit more if you posted some pictures of your setup.



    Actually there were a couple things that came up in this posting.. that to me remind me why i love
this game so much because how it closely mirrors real life in terms of traffic situations...

First of all and "z" alluded to this in and out of the posting, but I will try to be more specific...
But when sims first move in they basically move in as 1 of 3 catagories ...
i think these groups are selected randomly by the game and their isnt a whole lot you can do about it..
 
    1) sims that prefer their cars..
    2) sims that prefer mass transit
    3) sims that will take the shortest and fastest ? routes... using either cars or MT or a combination..

we all know there will always be people in real life where you could put mass transit right under their noses and
they still will drive their cars.. Also some people will use mass transit always because they may not have cars,
their cars are being repaired maybe, or gas prices are too high for them to drive..
Anyways, to me this all mirrors real lfe quite closely and its always been something ive loved being in the game..

   The other thing i saw come up which reminded me about real life, because we have a few of these here are
the "round abouts" in the game.. In real life its my understanding that those are always a pain in the rear end to drivers .. and always quite congested... Course in the game they look nice and are cool to build.. but yes to me
they actually mirror real life round abouts quite well...

anyways, i do obviously understand some people's frustrations about these things in the game , and as so many
times it just comes down to how you see the game really in general...

Thanks, Brian
Title: Release of Traffic Simulator Z - Beta 1 version
Post by: z on December 02, 2008, 01:04:02 AM
The Beta 1 version of Simulator Z is now completed, has undergone extensive testing, and is ready for general release.  A copy of this release is attached at the bottom of this post.  In the Alpha 4 release, I mentioned that there had been major improvements to the simulator since the Alpha 3 release.  The Beta 1 release contains equally major improvements compared to the Alpha 4 release.  At this point, the feature set is complete, and no major changes are anticipated between now and the final release.  Furthermore, the quality and reliability of this release is quite high; in all of the alpha releases, only two problems were found, one of which was an incompatibility with an unreleased NAM feature (which has since been fixed).  As a result, I expect few, if any, problems with this release, and it may very well turn out to be the final release.

Whereas when I first started working on this simulator, I saw it fitting only into a particular niche, the collective improvements I referred to above have made it applicable to all cities, towns, and rural areas.  I am now comfortable with calling it a next generation traffic simulator, and the title of this thread has been changed to reflect this.  Highlights of some of my most important tests are shown below.  The improvements to this release include the following:


Although a number of people have posted their experiences with Simulator Z in this thread, and some specific numbers have been posted, I have not posted the results of any specific tests myself.  I am doing so in this post first, to back up some of the more important claims I have made for Simulator Z, and second, to show the simulator is significantly different from Simulators A and B.  For all of these tests I am using the Beta 1 version of Simulator Z.  Beta 1 is much more flexible about routing Sims to their jobs; it uses the transportation infrastructure as efficiently as possible.  Specifically, it uses the new Load Stabilization Dynamics™ technique (LSD) to balance the transportation needs of Sims.  So although the simulator generally produces 2.5 to 6 times as much car traffic as other simulators (which is really nice if you plan to use the wider versions of RHW or NWM), in cities with very extensive mass transit systems Simulator Z has been observed producing fewer cars than Simulator B at a similar capacity.   As a result, there is no longer a separate "MT" version with Beta 1, as it is no longer necessary.  With the Sims using LSD for all their travel, their journeys seem to go by in a flash.  (This may also explain some of the accidents you see, although the accident rate in general is the same as before.)

For those knowledgeable about the simulator properties who are wondering what the heck Load Stabilization Dynamics is, it's just my name (chosen largely for its acronym) for an emergent property of the simulator that results from modifying a number of seemingly unrelated properties in a very special way.  Travel strategy percents were not changed, nor were speed limits raised; instead, the relationship between selected properties was changed.

One of the first questions that needs to be asked when we examine a traffic simulator is, What exactly are we trying to simulate?  Calculations based on reliable sources showing that a large tile with a population of 430,000 has the same population density as Manhattan, which is apparently the most densely populated place on the planet.  Other figures show that only 18% of Manhattan residents drive to work, while 72% take mass transit.  Having lived in Manhattan, I can believe those figures.  However, they don't take into account all the people who drive into Manhattan to work, which definitely boosts the percentage of people commuting by car, and therefore the number of cars on the streets.  (New York is the second most congested city in the U.S. in terms of road traffic, and that's New York City as a whole, so you can imagine what a mess Manhattan is.)

The problem here is that SC4 doesn't correspond very well to these figures.  Here's the Zones view of one of my Chicago cities, specifically the mostly residential Logan Square/Humboldt Park area:

(http://img266.imageshack.us/img266/385/lszoneswb8.jpg)

Most of the residential area is zoned medium density, with a much smaller amount low density, and one tiny square in the lower left quadrant is high density.  This is exactly what the zoning in this part of Chicago is like, with the exception that I had to put in a few high-density commercial areas to provide enough jobs for now.  But the residential capacity is zoned as closely to reality as the game will allow, and the resulting city looks somewhat similar to this part of Chicago.  This is far from downtown; it is certainly no Manhattan.  Yet the game population is approximately one million, many times higher than it should be.  So something's wrong here.

In one post, Tarkus says the following:

Quote
The game's counting of residential population is already over-inflated as it is, too, by a factor of about 2:1 or even 2.5:1.  David (dedgren) did a lengthy series of posts the game's scaling in terms of population and density as a part of his long-running Project Three Rivers Region which illustrate this concept very well.  He's in the process of moving the original posts from ST over here, but in the meanwhile, you can read about his thoughts on the matter starting on Page 31 (http://www.simtropolis.com/forum/messageview.cfm?catid=36&threadid=74819&STARTPAGE=31).

But an even more direct pointer to dedgren's conclusions is here (http://www.simtropolis.com/forum/messageview.cfm?catid=36&threadid=74819&STARTPAGE=32#937496).  I was unable to find Tarkus' ratios of 2:1 or 2.5:1 mentioned anywhere in either link.  However, at one point dedgren concludes (using Chicago as a model, no less!) that population density in SC4 is 10 to 20 times too high; in another example, he concludes it's 10 times too high.  This corresponds with my experience exactly.  Having built a half dozen tiles of Chicago exactly to scale, right down to the streets, with correct zoning, I estimate that if I ever finish it, the total population will be about 30 million - about 10 times too high.  So taking this into account, the aforementioned model of Manhattan-style transport would start applying to SC4 cities somewhere in the 4.3 million to 8.6 million range.

So what about everybody else?  According to the source jplumbley quotes, 88% of all travel in the U.S. is done by car.  This article (http://www.washingtonpost.com/wp-dyn/content/article/2007/01/26/AR2007012601589_pf.html) from the Washington Post repeats the 88% figure, adding that in Europe, the figure is 78%, but "Europeans are gaining on us."  The article adds that public transit accounts for 5% of travel in the U.S.; in Europe, it is 16% and declining.  One might assume that in big cities, more rapid transit is used, but that's not always the case.  Although New York City as a whole is the biggest user of mass transit in the country at 53%, Denver has only 5% mass transit usage, and Fort Worth, Tulsa, and Oklahoma City are all around 1%.  And at the top end, after New York City, the second highest mass transit user is Washington, D.C. at 38%, and the numbers go down from there.  (Source:  SustainLane.com's 2008 US City Rankings (http://www.sustainlane.com/us-city-rankings/categories/city-commuting).)

But who wants to build a city with SC4 that has only 5% or 1% mass transit usage?  Not many people, as such a city would have some of the best features of the game hardly used or not used at all.  So a realistic balance needs to be struck between realistic transportation usage and game enjoyment.  Ideally, the player should be able to build any type of city, and the game should respond in a realistic manner to the city's architecture.  I know that that is what the CAM and NAM teams (among others) have tried to do, and that is what I have tried to do with Simulator Z.

Now a good traffic simulator for this city should produce traffic patterns that are fairly realistic for the city I've shown above.  This city has virtually no subways, and one main elevated line running parallel to the blue diagonal (Milwaukee Ave.).  I've also restored the old Chicago Surface Lines, which are tram lines that run along the main avenues, each separated by exactly a mile.  Here's the Traffic Volume Graph for Simulator A (Easy) for when the city is in equilibrium:

(http://img266.imageshack.us/img266/158/lsams3.jpg)

Here's the traffic graph for Simulator Z, Beta 1:

(http://img266.imageshack.us/img266/2290/lszxg5.jpg)

The biggest difference, obviously, is the car volume, which is 3.75 as much in Simulator Z as in Simulator A.  The bus volume is about 25% higher in Simulator A, but this is a surprisingly small difference when you consider that buses count as traffic in Simulator Z.  The rail usage is identical in the two simulators, but elevated train and tram usage is 60% higher in Simulator Z.  The trams run at the speed of elevated trains (unrealistic, but not fixable), so the Sims are just being much smarter about taking the fastest method of mass transit in Simulator Z.  So Simulator Z has much more realistic car usage for an area like this, while simultaneously making much better use of mass transit.

So what about congestion?  I should mention that the current versions of Simulators A and B have a bug where congestion is not displayed properly; it is displayed as being much less than it actually is.  The congestion is still there; it's just not being displayed.  I have fixed the copy of Simulator A that I am using to eliminate this bug so that congestion is shown properly; no other properties of the simulator have been changed or affected.  I believe that this bug is going to be fixed in the next release of the NAM.

Here's the congestion map for Simulator A (Easy).  I ran it both with and without the congestion display fix; in this case, the results were identical:

(http://img266.imageshack.us/img266/7541/lsacongec6.jpg)

Notice that there's almost no congestion at all in the whole city.  (The red square is the Newman Hospital, which has a road that needs to be fixed.)  There's not even any yellow.  Just about the only congestion is the passenger rail line near the bottom of the graph, which is solid red.  How bad is this congestion?  If you look at the game view directly above the graph, you see that the rail line has 45,101 for the morning commute.  And the evening commute is even a little worse - it's a little over 46,000.  So that's over 91,000 Sims on a line with a capacity of 13,500, which means that the line is running at 674% of capacity.  And it stays that way, too.  This is true even on the unmodified Simulator A, which is supposed to prevent things like this with the low numbers in its Congestion vs. Speed curve.

Here's the congestion graph for Simulator Z:

(http://img147.imageshack.us/img147/2213/lsz2congmi8.jpg)

Notice that unlike Simulator A, there is slight congestion in some areas, which is just right for an urban residential area such as this.  The congestion also occurs largely around the high density areas, such as the lower left corner and just above the red square, along with a main commute corridor just to the left of the river near the bottom. This is basically what one would expect.  But the rail line that was so congested in Simulator A is not congested at all here.  This isn't just due to a difference of capacities - the actual use of this rail line in Simulator Z is only one third as much.  The Sims' commuting is just distributed much more evenly here, and is more realistic overall.

Finally, here is another view of the same area, taken with a larger picture so you can see where some of the actual congestion is.  Note that the larger picture shows congestion on routes in the commute corridor going from the residential area to the industrial area, which makes complete sense since this is rush hour.  (It's always rush hour!  :D)

(http://img266.imageshack.us/img266/9751/lsz1conghu9.jpg)

Now I'll move on to the Near South Side of Chicago.  Here is the Zones view:

(http://img241.imageshack.us/img241/9583/nsszonesym4.jpg)

Once again, notice that the vast majority of residential zoning is medium density, although there is a fair amount more of high density zoning than in the previous city, both residential and commercial.  The city's population is 1.9 million.

The next few pictures compare Simulator A at its Hard, Medium, and Easy settings with Simulator Z at its Low, Medium, and High capacity settings.  I have used the term "Low" rather than "Hard" because the Low setting may often be used in rural areas, where it is not difficult at all; conversely, there's nothing easy about using the High setting in a city of several million.  I should also mention that the extensive testing confirmed something of which I had previously seen only occasional evidence:  Simulator Z is much faster than Simulator A or B.  In this particular city, the game runs more than twice as fast at high speed when Simulator Z is used, and the difference in speed grows as the population of the city grows.  The reason for this is that I have been able to eliminate some of the exponential properties of the pathfinder which are still present in Simulators A and B.  And since the traffic simulator accounts for only part of the time it takes to run the game, a doubling of total game speed means that the traffic simulator is running about three to four times faster.

First I'll start with the congestion view of Simulator A (Easy).  In each set of views, I've included monorail usage at the exact same point for comparison.  All simulations started from the same point, and as you'll see from the traffic volume graphs, they were run until equilibrium was reached, which for this city took five years.  Monorail usage here is 5361, which is quite reasonable for this particular line.  Overall, there's a moderate amount of congestion for this city which is not terribly dense by SC4 standards, even on the Easy setting.  Most of the congestion is on roads, while the yellow going across the bottom is on one of the rail lines.  This is reminiscent of the rail line congestion in Simulator A shown in the previous city, though not as severe.

(http://img361.imageshack.us/img361/5263/nssahcongik8.jpg)

Compare the above picture to the one below, which is Simulator Z on its High setting, which has approximately the same road capacities as Simulator A (Easy).  There is some congestion, but it is just a small fraction of what shows up in Simulator A.  The reason for this is that the pathfinder is much smarter in Simulator Z.  For those familiar with the simulator properties, the Pathfinding Heuristic is lower, but that's only a small part of what's responsible for the difference.

(http://img204.imageshack.us/img204/1936/nsszhcongtv0.jpg)

Now let's look at the Traffic Volume Graphs, which shed a lot more light on what's going on.  As with the Data Views, Simulator A (Easy) is shown first.  The query tool report of a car volume of 9037 on the avenue is for the benefit of a NAM team member who said he had never seen an avenue volume much above 5200; here it is, and with the standard Simulator A.

(http://img361.imageshack.us/img361/1428/nssahhe7.jpg)

The graph below show Simulator Z; the monorail usage is only a little higher than that shown for the comparable version of Simulator A above.  But the graphs themselves are quite different; these are clearly very different simulators.  If you look at the above graph for Simulator A, ignoring the numbers, it has the various travel types aligned in approximately the same places that they were in the graph for Logan Square/Humboldt Park shown earlier; Simulator A uses approximately the same fixed proportions for travel types, even though the current city (the Near South Side) has twice the population of the previous city, and many more areas that are zoned high density.  But if you look at the graph for Simulator Z below, you see that not only is it quite different from the equivalent graph of Simulator A directly above, but it is also very different from the graph for Simulator Z for Logan Square/Humboldt Park.  In other words, by using adaptive heuristics, Simulator Z is able to take into account the different density distributions of the cities, and as a result it is much more able to route the Sims in a way that minimizes congestion while using the same capacity levels.  This explains the large difference in congestion shown in the two congestion views directly above, while the views and graphs for Simulator A show that it is unable to do this.

(http://img204.imageshack.us/img204/8214/nsszhnv9.jpg)

Now let's look at the above graphs in detail.  It's important to remember that these graphs show trips, and multiple trips may make up a single commute.  This is one reason pedestrian usage is so high - if you walk to the bus from your home and then from the bus to work, that counts as two pedestrian trips plus one bus trip.  So the numbers in these graphs can't be mapped to numbers of commutes in any way that results in complete accuracy.  However, by comparing the graphs for a single city at a given time from two different simulators, it's possible to get a very good idea of how the simulators are routing Sims.  And in fact, the results one gets from such an approach match up very well with the congestion views.

In posts about earlier versions of Simulator Z, I reported that car usage ranged from 2.5 to 6 times as much as in other simulators.  And in my Logan Square/Humboldt Park city above, the ratio is 3.75, which is well within this range.  But the beta version of Simulator Z is much more flexible, and will adjust car usage over a much wider range.  By comparison, car usage in Simulator A is rather inflexible.  For example, Simulator A's car usage in the Near South Side is essentially twice that of its car usage in Logan Square/Humboldt Park, reflecting the relative size of the cities.  By contrast, Simulator Z's car usage in the Near South Side is only 20% higher than in Logan Square/Humboldt Park.  This results in a ratio of car usage between Simulator Z and Simulator A of 1.36 in the Near South Side, well below the lower margin of 2.5 reported for previous versions of Simulator Z.  Why does this happen?  Although Simulator Z has a strong preference for car usage, this preference is overridden when it would cause unbalanced traffic flow resulting in congestion.  From the player's point of view, it appears that traffic is getting heavy enough that the Sims decide that they would rather take public transit.  As you can see from the congestion views, this flexibility does not exist in Simulator A.

There is one other significant difference between the two traffic graphs above.  If you compare them, you'll notice that bus and subway usage have pretty much switched places in the two graphs.  Simulator A relies far more on buses, while Simulator Z relies far more on subways.  Simulator Z's approach seems to make sense, in that subways are far faster than buses.  The success of this approach is verified in the congestion views above.

Now let's look at the same city run at Medium difficulty in both simulators.  Once again, road capacities are basically the same.  Here's the congestion view for Simulator A:

(http://img516.imageshack.us/img516/9393/nssamcongzj9.jpg)

And here's the congestion view for Simulator Z:

(http://img516.imageshack.us/img516/4228/nsszmcongmq7.jpg)

The differences are much greater than in the previous case.  There is significantly more congestion in Simulator A, but in Simulator Z, the congestion increase is hardly noticeable.  In fact, it takes a bit of examination between the two Simulator Z views to see that there is actually a small increase in congestion in the Medium simulator.

Here are the corresponding Traffic Volume Graphs.  First, Simulator A:

(http://img516.imageshack.us/img516/5199/nssamzc3.jpg)

And Simulator Z:

(http://img516.imageshack.us/img516/5431/nsszmwd5.jpg)

First, notice the monorail usage for the two simulators.  Simulator A reports no monorail usage at all, while Simulator Z reports a moderate usage of 3222.  So in Simulator A, even though network capacities have decreased and congestion has increased significantly, Sims have abandoned the monorail!  Why?  As mentioned in an earlier post, the monorail is a very tricky network, and requires special tuning over a number of simulator properties to work optimally.  Simulator A does not have this special tuning.

As for the graphs in general, notice how Simulator Z's Traffic Volume Graph is almost identical for Simulator Z above at the High capacity.  So even through these graphs are greatly different from Simulator Z's Traffic Volume Graph for Logan Square/Humboldt Park, it shows that once Simulator Z has figured out an optimal traffic distribution for a city, it sticks with it.  This makes sense, as anything significantly different would be, by definition, less than optimal.

The story is quite different for Simulator A, though.  The graph for Medium capacity looks very different from the graph for Easy capacity, shown earlier.  Car traffic throughout the city has dropped by 40%.  Bus traffic has dropped by 21%.  Since in Simulator A, buses don't contribute to traffic but are affected by it, this means that the significant increase in congestion from car traffic is slowing buses down enough to force Sims off them and to alternate transportation routes.  And where are they going?  To the subway, along with a lot of former car commuters.  Subway usage is up 292% compared to the Easy version of Simulator A, and is now much closer to that of Simulator Z.  Yet the fact that there is still much more congestion with Simulator A shows that distribution of travel types is only part of the picture.  The actual pathfinding in Simulator A is still not sufficient to come anywhere near the efficiency of Simulator Z, as shown in the congestion graphs.

Now let's run this city with the Hard version of Simulator A, and the Low capacity version of Simulator Z, which actually has a slightly lower road capacity than the Hard version of Simulator A.  But let's also throw in another congestion view for comparison, so we can see how Simulator A compares to the Maxis simulator.  For the first view, I have taken the Maxis simulator, but replaced its network capacities and maximum commute times with those of Simulator A (Hard):

(http://img204.imageshack.us/img204/1530/nssmcongyt6.jpg)

Now here's the Simulator A congestion view:

(http://img361.imageshack.us/img361/83/nssalcongie6.jpg)

Note that although congestion in the two above views occurs in somewhat different places, the overall amount of congestion is very similar.  The Maxis congestion view has slightly less congestion in the upper left quadrant and lower right quadrant, while it has more congestion in the lower left quadrant.  (The upper left quadrant is just as colorful in the two views, but in the Maxis view, there is much more yellow, compared to the red of Simulator A.)  The two views are quite similar in total levels of congestion, despite the fact that the top view is merely the plain Maxis traffic simulator using the network capacities and maximum commute times of Simulator A (Hard).

From the above tests, this surprising conclusion emerges:  When run with identical network capacities and maximum commute times, there is no significant difference between Simulator A and the vanilla Maxis simulator in terms of traffic congestion and congestion dispersion.

Now someone might say, "OK, to be fair, what does this city look like if you use the Maxis simulator with Simulator Z's network capacities and maximum commute times?"  This is certainly a fair question.  On one hand, with Simulator Z's higher rail capacities, which were justified near the beginning of this post, you would expect to see a reduction in congestion.  After all, it's only the network capacities that differentiate the different levels of Simulators A, B, and Z.  But if plugging these numbers in results in a congestion view which is essentially the same as Simulator Z's, then Simulator Z is clearly not doing any better than Simulator A when compared against the vanilla Maxis simulator.  So first let's plug in Simulator Z's numbers and see what we get.  We also make buses count as traffic, since Simulator Z's capacities are based on this being true.  Here's what we get:

(http://img212.imageshack.us/img212/7696/nssmzlcongfr2.jpg)

Well, this is a different sort of mess.  If there's a reduction in overall congestion, it's not significant.  It's hard to say whether the overall congestion is more or less than the previous views, although it certainly seems to be in the same ballpark.  But this congestion is distributed over a much wider area, resulting in more yellow and less red.  The traffic flow is more balanced, although it is still at its worst in the areas zoned high density, as it should be.  This supports my contention that the rail numbers in Simulators A and B are too low, resulting in an unbalanced traffic flow.

But what about the congestion view using the full Simulator Z?  Here it is:

(http://img361.imageshack.us/img361/7161/nsszlcongxc2.jpg)

It's clear that this view contrasts greatly with the previous three congestion views.  So unlike Simulator A, Simulator Z significantly outperforms the vanilla Maxis simulator even when the latter is using identical network capacities and maximum commute times.  This should demonstrate conclusively that there are major strategies at work in Simulator Z that are not present in Simulator A.  But just to completely prove this point, let's take Simulator Z's network capacities and maximum commute times and stick them into Simulator A.  Once again, since Simulator Z's capacities are based on buses' counting as traffic, they count as traffic here.  Here is the result:

(http://img185.imageshack.us/img185/1540/nssazlcongdi8.jpg)

It's a little better than the standard Simulator A view (second in this series), but not much.  And it's still far more congested than the Simulator Z view directly above.

As a side note, I should point out that neither the Medium nor the Hard versions of Simulator A were designed or recommended to run on a city of almost two million.  So what I'm doing here is essentially a stress test - running these simulators in difficult situations to amplify effects that might otherwise be difficult to see.  On the other hand, Simulator Z at similar capacities does fine in this city.  So you may interpret that as you will.

Comparing the unaltered Simulator A and Z views above to the earlier, higher capacity ones, we see that the Simulator A (Hard) congestion view above shows considerably more congestion than Simulator A (Medium), with many yellow areas turning to red, and other areas showing congestion for the first time.  This, of course, is not surprising.  Simulator Z on Low capacity also clearly shows more congestion than Simulator Z (Medium).  However, what is striking is that Simulator Z on Low capacity, which is comparable to Simulator A (Hard), shows less congestion than Simulator A (Easy), which is displayed at the beginning of the Near South Side series.  It is hard to think of a more dramatic contrast between the two simulators than this.

Meanwhile, we can also see the difference between the two simulators in monorail usage on their lowest capacity levels.  Above the congestion view of Simulator Z, we see a monorail usage of 7821, which as before, is normal for this line.  In fact, it's the highest monorail volume we've seen for the monorail on Simulator Z, which makes sense, as the other networks are starting to get a bit crowded.  But directly below, right above the Simulator A graph, we see a monorail usage of 134.  Once again, the reason for this is that Simulator A is not tuned to use the monorail properly.

Now let's look at the graphs themselves.  First, as usual, Simulator A:

(http://img361.imageshack.us/img361/9346/nssalxb6.jpg)

And now, Simulator Z:

(http://img361.imageshack.us/img361/4989/nsszlvr3.jpg)

Once again, the Simulator Z graph looks almost identical to its predecessors.  It's got a good traffic distribution, and it's not going to mess around with it.  And this time, Simulator A's Traffic Volume Graph looks very similar to its previous one.  Basically, Simulator A has done the best it can do.  But if you look at the congestion graphs above, you see that compared to Simulator Z, its best is not very good.

Now some people, when looking at the congestion view of Simulator Z at Low capacity, might think that it does its job too well.  If even in a city of nearly two million there's barely any congestion, where's the challenge?  The answer is simple.  This city was built before Simulator Z was developed, and it has a vast system of public transit.  Specifically, it has a very large system of underground subways.  That doesn't affect the previous comparisons, because both simulators had equal access to the subways.  But now let's turn the subways off.  The switch is around here somewhere... %confuso  There!  Now we rerun the simulators just the same as the last run, except there are no subways.  If you think traffic was bad last time, look at this.  First, Simulator A:

(http://img101.imageshack.us/img101/1957/xnssacongan2.jpg)

And now Simulator Z:

(http://img101.imageshack.us/img101/3176/xnsszcongsi5.jpg)

Overall, Simulator A has worse congestion than when the city had subways, but not uniformly.  For example, some of the big red patches in the upper left are gone.  Why should there be less congestion in some areas just because the subways are gone?  As for the monorail, its volume is now back up to 6308.  But with the subways out of commission, you'd expect much higher use than that for the monorail.  Indeed, in the Simulator Z view, monorail usage is up to 47,055.

Meanwhile, congestion in Simulator Z is substantially worse compared to previous runs.  If you look closely, you see it's still not quite as bad as that in Simulator A, but it's close.  Why did it lose its huge advantage over Simulator A?  The answer is one word:  Buses.  Like all other simulators, Simulator A uses buses leased from Simgularity Bus Lines.  These buses have the unique property that you can stuff as many Sims as you want into them, and never run out of space.  Yet at the same time, the buses are infinitesimally small, so they have no effect on traffic, although they are affected by it.  They're a little bit like black holes on wheels.  But Simulator Z uses standard city buses, which contribute to traffic.  And therein lies all the difference.  With the subways gone, Simulator A can stuff more and more Sims into buses without increasing traffic.  Even so, overall congestion increases significantly.  But Simulator Z is more realistic in this respect and has no such free option, so congestion increases even more.  Still, Simulator A's ability to stuff unlimited numbers of Sims into congestion-free buses is not enough to give its city overall less congestion than Simulator Z.

For a better comparison of the two simulators, let's level the playing field a bit and rerun the last simulation with Simulator A, except this time we'll make the Sims take regular city buses:

(http://img361.imageshack.us/img361/4881/xbnssacongvf5.jpg)

This view is directly comparable to the congestion view directly above it, which uses Simulator Z.  And of course, the one above that is Simulator A where buses don't contribute to traffic.  So it doesn't look like it's a good idea just to turn this feature on in Simulator A - I had to link it to too many other features in Simulator Z to make it work.  This is why you can't just look at properties individually - they all tie in together.   Simulator Z works as an integrated whole, and taking pieces of it just doesn't work.

Meanwhile, let's go back to that last congestion view using Simulator Z where the subways are turned off.  For those who like a challenge, Simulator Z certainly offers one here.  In reality, the Near South Side of Chicago has only one subway line running through it, so this view is more realistic in that respect.  But the simulator is running on its lowest capacity here.  For a situation like this, you'd want to run it on Medium, or maybe High to get realistic results.  And if you're trying to model a city like Denver, where only 5% of the population uses public transit, the Ultra simulator is the one to use.  The Ultra simulator is also useful if you're playing a city with a lot of intercity traffic, as you're dealing not only with your own city's traffic, but with traffic from other cities as well.

Does this mean that Simulator Z loses its advantage over Simulator A in cities without subways?  Not at all.  If you recall the first congestion views in this post, which were of Logan Square/Humboldt Park, you'll remember that Simulator Z showed a more realistic congestion pattern than Simulator A.  And as I mentioned at the time, this is in a city with essentially no subways.  So game realism is increased in all settings.  And if you gradually add subways to a congested city, the amount of congestion shown by the two simulators rapidly diverges, as the pictures of the Near South Side show.  To encourage more realistic subway use, and to make the game a little more challenging in a realistic way, I quadrupled the monthly cost of subway tiles back in the Alpha version.  So overall, the Sims are much smarter about how they travel, but the limits on their transportation systems (specifically buses and subways) are a bit more realistic.

So that's it.  I hope I've made my case that Simulator Z really is a next generation traffic simulator.  This post has concentrated on only a few topics, namely the ones that are easiest to display in static pictures and graphs.  But I think you can get a feel from this post that traffic is handled in a very different way from any other simulator, and this is very apparent during game play.  One of the things I hear most often from users of this simulator is that their traffic flow is more balanced and realistic.  I think the pictures and graphs in this post help show why this would be so.


A Request

What happens next is up to you, the players of this game.  First of all, if this sounds at all interesting, you can download the latest version of Simulator Z from the bottom of this post.  I would appreciate feedback from everyone who uses this simulator, including any problems you may have.  (You shouldn't have to worry too much about this; there have been no known bugs for the last two versions.)  And along with feedback, there's a very important question I would like to ask the community.  If this traffic simulator really has unique advantages, as I have tried to show, or even if it is simply preferred by many users, as comments throughout this thread show, do you think this simulator belongs as a standard part of the NAM, along with Simulators A and B?  I am not a member of the NAM team, and understandably, they are not going to include this simulator in the NAM just because I ask them to do so.  But if enough people make it clear that they'd like to see this simulator included in the NAM, I think it could make a real difference.  So if you'd like to see this as an option, please post in this thread, even if you haven't actually used the simulator.  Also, I consider the Traffic Volume Views enclosed with the simulator to be connected to it, so if you would like to see them in the NAM, please mention that as well.  Thanks!

Meanwhile, here's the simulator - Enjoy!

EDIT:  This version of the traffic simulator has been superseded.  You can get the current version here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=4809).
Title: Re: A Next Generation Traffic Simulator
Post by: b22rian on December 02, 2008, 07:01:38 AM
Hello Sim 4 devotion community.. and good day to you !

After several weeks of testing and now using Traffic sim Z..

I have now made the switch over to it from formerly using traffic sim's B and A..

I would like to fully endorse its use by all for the following reasons...

the reasons are on a comparative type basis after many months of testing and using traffic sim's A and B

on the hard difficulty settings, from the time those sim's were released for use..


1) .. A more balanced traffic type distribution patterns through-out my cities..

2) ...a higher percentage of car usage compared to traffic sim A as i eagerly await the super- highways
       of the RHW 3.0 release..

3)... very strong usage of all my mass transit systems.. Including higher monorail usage to the tune of 30 K
      increase over sim A.. ( I have a complex and extensive monorail system in my largest city..)
 { One may ask here how can you have both a higher car and mass transit usage for a given population ?..
    a fair question.. but the reason I give for this is.. because in sim Z , ive noticed that sims will look for
    a find the most efficient routes to and from work..often times this involves mutliple forms of transit on
    a given trip..So where as previously in sim A a sim would put up with simply driving a car all the way
    into work being throttled by long traffic jams.. The now smarter sim in the traffic Z enviroment will
   take advantage of multiple forms of mass transit if necessary to reach his destination quicker.. Although
   to best take advantage of these types of things, one must have planned and constructed the proper
   transport options in their cities..i may add.}

4).. so as a result better pathfinding in sim Z..

5) .. there is less game lag using sim Z than other traffic sims..

6).. and this should come as no surprise to anyone..but better zone development across the  board
      for the 3 zone types and higher populations.. being that "traffic" is such an integral part of sc 4.
   

also, I would like to encourage the addition of Sim Z into the inclusion of the next Nam release as a viable
option to the other traffic sim's.. And I encourage all to at least give sim Z a try , and make their own
decision as to if they want to use it as their traffic sim.. I can only tell you that ive used many of the
traffic sim's for years now playing this game.. and i would not go back to using any of them now that I
am using traffic sim Z..

Id like to hear some feed back from others as to what they think ?

thanks , Brian
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 14, 2008, 08:41:18 PM
I am pleased to announce the return to this thread of my post announcing the Beta 1 release of Simulator Z, along with a downloadable version of the simulator itself.  The post also includes the results of extensive tests (with LOTS of pictures), illustrating how different simulators perform in different situations.  I made the tests especially extensive to answer some of the questions that I thought might arise, and some of the results were quite unexpected.  This post contains the most extensive testing of my simulator of any post in this thread, and for that reason, as well as for the Beta 1 release announcement, I consider it to be one of the most important posts in this thread.  It's located two posts before this one, but as it is quite long, you may find it easier to reach it by clicking here (http://sc4devotion.com/forums/index.php?topic=5382.msg204681#msg204681).  Although there are many tests shown, they cover only the parts of the simulator that were easiest to display.  I think that Brian's post, directly above this one, gives a well-rounded picture of what a typical user can expect to see with this simulator.

No problems are known to exist in the new Beta version of the simulator, and barring any surprises, this is the version that would be submitted to the NAM Team, should they decide to evaluate it.  So for those interested in this simulator, happy reading of the restored post, and I think you'll like the new version of Simulator Z.
Title: Park and Ride (Release of Traffic Simulator Z - Beta 1A version)
Post by: z on December 15, 2008, 06:00:47 PM
I have added Park and Ride versions to all four variations of Simulator Z, making a total of eight simulator versions.  The Park and Ride feature of Simulator Z is identical to the Park and Ride feature of Simulators A and B.  What this means is that with these new versions, cars are not allowed to carry Sims all the way to their destinations (even if their destinations have those beautiful little built-in parking garages in back).  Instead, to make maximum use of this feature, you need to construct adequate parking space near mass transit stations in residential areas.  (Some stations, such as the Maxis train station, already have parking included.)  I have found RalphaelNinja's Ninja Boulevard Station (http://www.simtropolis.com/stex/details.cfm?id=3194&v=1#) and Ninja Boulevard Kiosk (http://www.simtropolis.com/stex/details.cfm?id=3195&v=1#) to be very useful in general, and particularly useful for Park and Ride, as they both contain large underground garages.  I have enclosed modified lot files for both of these stations; the modifications bring the monthly cost down to be more in line with similar stations, and they also double the capacity, bringing them more in line with RTMT (and making them especially useful for Park and Ride).  Since the exquisite design of these stations must have cost a lot of money, I left the plop cost alone.  Also, since I have enclosed only the lot files, if you don't have these stations already, you'll need to download them from the above links.

Park and Ride has a couple of other tricks that you might want to try.  If you use Park and Ride but don't build any extra parking (and don't use stations that have parking incorporated), you basically force your Sims to use mass transit.  In this case, you would want to have a very extensive mass transit system.  And if you use Park and ride with no public parking and no mass transit, you end up forcing your Sims to walk to work.  (It's basically Park and Ride with no place to park and nothing to ride.)

The package I've enclosed here is identical to the previous release, except for the addition of the Park and Ride versions and the revised Ninja Boulevard station lots.  If you have the previous release and are not interested in these additions, there's no need to download the current release, as the standard simulator versions have not changed at all.  But for those who want Park and Ride, now it's here.
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 18, 2008, 11:29:33 PM
Hello z,

I too am making creating a region based on a real world city.  I started using this simulator a few weeks ago.  I chose the Low setting, and I have tested it from the suburbs through to major employment areas.  This beta version is the best traffic simulator I've used yet (not saying that it's perfect, but it has strong advantages over other simulators).  The first and most obvious thing I did notice is the game (unpaused) runs much faster than the previous alphas and Sim A or B.  On top of that, more often than not, the route query seemed to be updated much quicker (a few weeks to a few months, rather than several years).

I do agree with your reasoning for increasing capacities.  I would like to add that since SimCity only simulates rush-hour traffic, and that the traffic is simulated as such as if it were occurring all at once, I do not believe treating network capacities as if they were per-hour is the correct action to take.  But I do admit there has to be the "challenge" element (isn't replicating a metro area enough?) and the simulator has to fit a wide range of uses.  I'm glad you have made the Low/.../Ultra versions to address these.
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 21, 2008, 10:06:16 PM
To z,

I'm still testing out the simulator.  I've been having some and quirky behavior (patches of chronic abandonment and a few instances of commuters flocking to a city tile with no jobs), but I can't discount nor blame the simulator as cause.  Also, there are still instances of mass commuters taking the shortest route to/from a neighbor connection, and a few places where the spreading behavior is occurring where it is not desired.  I can post pics if you are interested.

I'm quite curious about the congestion view and your new traffic view.  Under a non-z-simulator configuration, I didn't have much of a use for the traffic view, and the congestion view alone (usually) told me about trouble spots.  Now, my cities are mostly full of green roadways in congestion view.  But the route query and traffic view tell a whole other story.  In both rush-hours, as expected, major arterials and bottlenecks are red as can be, while side and cross streets show up orange and yellow.

I'm nowhere knowledgeable as you or the NAM team about the traffic simulator.  Is there a sort of ultimate limit on streets relative to the stated 100% capacity of a roadway?  In other words, is there a % limit?  I know of the 65535 showable digit limit for highways, but you could still add vehicles to it and development would still continue.  I'm asking because of these patches of chronic residential abandonment.  It happens across all 3 wealth types in the same area.  This is an issue I've also had with Simulator A and B.  I do not believe it is due to a lack of available appropriate jobs since I have job lots within the same city with no workers.  Also, I can still build in other areas, up to a point.  I think I can attribute it to bottlenecks and a huge influx of neighbor commuters.  I don't believe I have eternal commuters because the region I'm building is quite linear.  I've tried using the higher capacity versions and I've settled on Medium.  Raising the capacities somewhat lessens abandonment, but it increases the chance of commuters flocking to a wrong neighbor connection and spreading where undesired.
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 22, 2008, 03:45:47 AM
To z,

I'm still testing out the simulator.  I've been having some and quirky behavior (patches of chronic abandonment and a few instances of commuters flocking to a city tile with no jobs), but I can't discount nor blame the simulator as cause.  Also, there are still instances of mass commuters taking the shortest route to/from a neighbor connection, and a few places where the spreading behavior is occurring where it is not desired.  I can post pics if you are interested.

I'm quite curious about the congestion view and your new traffic view.  Under a non-z-simulator configuration, I didn't have much of a use for the traffic view, and the congestion view alone (usually) told me about trouble spots.  Now, my cities are mostly full of green roadways in congestion view.  But the route query and traffic view tell a whole other story.  In both rush-hours, as expected, major arterials and bottlenecks are red as can be, while side and cross streets show up orange and yellow.

I'm nowhere knowledgeable as you or the NAM team about the traffic simulator.  Is there a sort of ultimate limit on streets relative to the stated 100% capacity of a roadway?  In other words, is there a % limit?  I know of the 65535 showable digit limit for highways, but you could still add vehicles to it and development would still continue.  I'm asking because of these patches of chronic residential abandonment.  It happens across all 3 wealth types in the same area.  This is an issue I've also had with Simulator A and B.  I do not believe it is due to a lack of available appropriate jobs since I have job lots within the same city with no workers.  Also, I can still build in other areas, up to a point.  I think I can attribute it to bottlenecks and a huge influx of neighbor commuters.  I don't believe I have eternal commuters because the region I'm building is quite linear.  I've tried using the higher capacity versions and I've settled on Medium.  Raising the capacities somewhat lessens abandonment, but it increases the chance of commuters flocking to a wrong neighbor connection and spreading where undesired.

Some of what you're describing sounds like it might be caused by unbalanced demand.  So first, I have three questions:  1) What is your regional population?  2) Are you using CAM?  3) What are your tax rates for this city?

Next, it would be very useful if you could post a picture of the output from either the Census Repository Facility or the Census Repository Vault for the city in question.  If you don't have these buildings, you can find them here (http://sc4devotion.com/csxlex/lex_filedesc.php?lotGET=1831); if you're just installing this for the first time, the easiest thing to do is use the Vault.  Also, posting a picture of your RCI demand graph would be helpful; although the data is basically contained in the Census Repository, there are certain patterns that I find easier to recognize in the graph form.

The case of mass commuters taking the shortest route to or from a neighbor connection is inherent in the built-in traffic simulator engine, and cannot be fixed.  If it could, then the eternal commuter problem could be fixed as well.

You say there are "a few places where the spreading behavior is occurring where it is not desired."  A picture with an explanation would be very helpful here.

As for the traffic volume view, your results are a bit puzzling here.  They would make sense if you were using Simulator A or B, but I gather that you're describing a situation with Simulator Z.  Are you using the optional Traffic Congestion View that comes with the NAM?  If so, try removing it and see what your results are.  To find it, look in your Network Addon Mod subfolder in your Plugins folder, and see if the file NetworkAddonMod_Congestion_Data_View.dat is there.  If it is, remove it.

If that's not your problem, please post some pictures with queries, and we'll see what we can figure out.  I have not heard of this problem before with Simulator Z.

As for capacities, all networks have a hard limit of 65,535 in terms of a volume that can be displayed during a commute period.  However, as you gathered, you can have higher volumes than that; they just don't show up in the query (or in the Traffic Volume View, which simply reflects the query.)  Other than that limit, there are no other hard limits in terms of absolute numbers or percentages.

I've seen the same type of chronic abandonment that you have in certain areas.  You mentioned that you've noticed it in a number of simulators, which makes sense to me.  Either it's a demand imbalance problem, which the output of the Census Repository will show, or else it's a limitation in the basic traffic simulator engine, upon which all traffic simulators are based.  Based on my own experience, I don't think it's likely to be in the traffic simulator engine.  But again, your pictures will tell us a lot.

One final question:  You said you had the same abandonment problem with Simulators A and B.  Was the problem using these simulators more, less, or about the same as when you use Simulator Z?  The answer to this might help to pin down the problem.
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 22, 2008, 07:58:16 PM
To z,

1. My current region population is 790,577.
2. Nope, I'm not using CAM.
3. Tax rates are all 9% except for R$$$ at 12%

I re-ran all of the inhabited city tiles in the region for about 2-3 years each and then resaved them.  I was quite surprized that the traffic was generally performing the way I wanted to, and many of the quirky behavior was gone.

However, there is one persistant quirk.

(http://img389.imageshack.us/img389/5986/freewayquirkzg4.jpg)

I don't know if it's some sort of joke the Sims are pulling off.  1600 cars are going into that dead end street and turning around.  I know this isn't a normal because this area is the SimCity equivalent of my neighborhood.  To the right are neighbor connections, jobs are southwest.  There is a closer offramp to jobs, but the roadways there are more congested.

I've removed the NAM congestion views and data views.  I had a THL Data View More Detail dat, but there was no difference when removing it.  But since I resaved the city tiles, congestion view has worked as expected; there are much more areas with yellow, orange and red.

Yes, using Simulator Z has greatly lessened the spread of abandonment and dilapidation.  Compared to now, previously with A and B, there was a smaller population (< 500,000) and more jobs.  I had less congestion.  Abandonment occured in many cities, both mixed-zone job centers and suburbs.  Many commuters just commuted to neighbors.  It almost reached the point of eternal commuters, and I had to implement stop-gaps, but doing that further spread abandonment.  I think there might have been some 'residue' in some of the cities I could have not resaved with Simulator Z.  Abandonment is now limited to 3 city tiles (one job center and two consecutive tiles to the right).

This is from the job center tile in question:

(http://img233.imageshack.us/img233/885/censusob0.jpg)

(http://img218.imageshack.us/img218/3702/rcigraphqd8.jpg)


I think a huge fault of mine in regards to demand, and it probably has to do w/ the Residential Halver and Industry Quadrupler plugins.  When I first started the region in January 2008, I did not have them installed.  After starting to build out the job center tiles, I installed them, but later removed the Industry Quadrupler.  I did manage to find a thread at Simtropolis where RippleJet said along the lines of halving an existing residential population would turn them into commuters and would mess up demand.  However the demands are quite high (R$$$ is only low in this city tile due to taxes; it's well above 5000 elsewhere), and it's not like I can't build development.  I've managed to "get rid" of abandonment in all of the other city tiles.  It's just that in the 3 city tiles, certain areas still tend to abandon and/or dilapidate.

Thanks for helping.
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 23, 2008, 01:52:08 AM
Well, the good news is that there's nothing to indicate any problems with the traffic simulator here.  Also, I don't see anything here that can't be fixed.

I think a huge fault of mine in regards to demand, and it probably has to do w/ the Residential Halver...

Yes, that will do it.

Quote
I did manage to find a thread at Simtropolis where RippleJet said along the lines of halving an existing residential population would turn them into commuters and would mess up demand.  However the demands are quite high...

But from the end of your previous message:

Quote
Raising the capacities somewhat lessens abandonment, but it increases the chance of commuters flocking to a wrong neighbor connection and spreading where undesired.

This sounds to me strong evidence of what RippleJet was warning about.  The idea of the Residential Halver is good in principle, but a number of people have found it just doesn't work well with the game.  You should definitely get rid of it.  Also, if RippleJet says something, especially if it has to do with demand, please, believe him.

So I think a lot of your problems, including the transitory ones, are due to the Residential Halver.  I would also not recommend reinstalling the Industry Quadrupler.  Instead, I would strongly recommend installing CAM 2.0 when it comes out.  I wouldn't install the current version at this point, simply because it's going to be completely incompatible with CAM 2.0.

The THL_DataViewMod_MoreDetail.dat is a very nice mod, and I've never had any problems with it.  You should feel free to reinstall it without worrying about any problems.

It sounds like removing the NAM Congestion View fixed your congestion problem.  This file is known to be broken, and is scheduled to be fixed for the next NAM release.  I think that what you're calling the NAM data view is actually my Traffic Volume View; if so, you can safely replace it.

I gather from your message that when you installed Simulator Z, your population increased almost 60%.  This is consistent with what other people have seen with this simulator; it's a result of the increased pathfinder optimizations, which is also what's responsible for lessening the spread of abandonment and dilapidation in your city.  But if your transportation network is unchanged, it's not surprising that this would cause additional congestion.  You may need to do some upgrading here; adding some rapid transit would help a lot.

As for that street in the first picture, the cars aren't actually turning around; the built-in pathfinder prohibits Sims from ever retracing their routes.  The animated cars may be turning around there, but their actions rarely tell you what's really going on.  Still, the volume of 3185 at the end of the street is surprisingly high; there's probably something illegal going on there. ;D  Seriously, if you want to know where all the traffic is coming from, you'll need to do a route query on the buildings around there.  But again, this is not a traffic simulator problem; the simulator is simply taking the Sims that live there and routing them out to their jobs.  The incoming traffic looks a little spurious; my guess is that there's some building there that has a few jobs that are being filled.
Title: Re: A Next Generation Traffic Simulator
Post by: Swamper77 on December 23, 2008, 02:05:49 AM
As for that street in the first picture, the cars aren't actually turning around; the built-in pathfinder prohibits Sims from ever retracing their routes.  The animated cars may be turning around there, but their actions rarely tell you what's really going on.  Still, the volume of 3185 at the end of the street is surprisingly high; there's probably something illegal going on there. ;D  Seriously, if you want to know where all the traffic is coming from, you'll need to do a route query on the buildings around there.  But again, this is not a traffic simulator problem; the simulator is simply taking the Sims that live there and routing them out to their jobs.  The incoming traffic looks a little spurious; my guess is that there's some building there that has a few jobs that are being filled.

Z,

The traffic going to the dead end street to turn around could also indicate a pathing problem. In their case, it looks like there is a pathing problem with the diagonal One Way Road intersecting the orthogonal street.

There were a few problems like this when Rush Hour came out. In those very few cases, Maxis had omitted paths to allow the vehicles to travel in specific direction. The vehicles would go down a dead end street to get to a side of the intersection that would allow them to travel in their intended direction. I don't have the pictures handy, but I do recall there was an issue specifically with a diagonal road intersection that would not allow vehicles to turn left from the diagonal road. The old Transit Bugfix files fixed these pathing issues. They are currently in the NAM's files somewhere as all the old Transit Bugfixes have been incorporated into the NAM long ago.

-Swamper
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 23, 2008, 02:43:15 AM
Swamper, what you say makes a lot of sense, and really answers all the questions about what's going on here.  It would mean that Maxis modified their implementation of the Manhattan A* pathfinding algorithm to allow path retracing in certain cases, but I gather from what you say that this has definitely been observed with dead-end streets before.  And as this particular configuration is a bit unusual, especially with the custom NAM off-ramp, and since most people don't do route queries that often, I can see how this would have been missed until now.

So who gets to fix this?
Title: Re: A Next Generation Traffic Simulator
Post by: Tarkus on December 23, 2008, 02:49:23 AM
sumwonyuno, would you be able to show a pic up close of that Diagonal Elevated Highway/OneWayRoad exit ramp there with the DrawPaths cheat (included in Buggi's ExtraCheats.dll file)?  That would help us ascertain what's going on with the actual transit path files and see if they are the cause of your problem.

-Alex
Title: Re: A Next Generation Traffic Simulator
Post by: b22rian on December 23, 2008, 06:09:06 AM
To z,



I re-ran all of the inhabited city tiles in the region for about 2-3 years each and then resaved them.  I was quite surprized that the traffic was generally performing the way I wanted to, and many of the quirky behavior was gone.



I know this sounds kinda amazing.. But ive noticed when doing testing .. most changes do occur in the 2-3 time
frame you mentioned.. but I have seen some changes continue to evolve up to about 5 years of game time or
so.. the pathfinding is quite complex, so I can't say im too surprised about this.. But I would recommend going
about 5 years just to be sure of any sort of change to traffic..conditions..

thanks, Brian
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 23, 2008, 04:05:28 PM
Brian is right here.  During my simulator testing, I had to switch between simulators (or different versions of the same simulator) many, many times.  It usually took about five years for the switchover to be complete.  During this time, the routes used by the game would gradually change from the routes used by the old simulator to the routes used by the new one.  The reason that the change takes so long appears to be due to the anti-herding behavior built in to the Maxis traffic simulator.  It will only change a certain number of routes at a time, so as not to flood the most popular routes with Sims, only to have to redistribute them on its next pass.  This gradual change can easily be seen on the Traffic Volume graph; the changes are most apparent using the five-year timeline.  A while after the simulator change, you'll see an initial adjustment of the traffic volumes, which shows up as a square 'U', followed by a stair step pattern in many of the traffic volume lines.  In the cases I looked at, each step was a bit less than a year long.  This pattern typically lasts for about five years in a big city; when the lines flatten out, and there is little or no change for over a year, the transition is complete.
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 23, 2008, 09:14:01 PM
To z,

I do realize I have steered the thread away from the simulator by talking about demand (not that I've been warned or anything).  I will post in the appropriate topic if I do have any more demand issues, since we've been able to contain it as another problem.

The good news at least is it isn't your traffic simulator that caused any of the problems.  By the way, the 60% increase in population was because after I switched to simulator z, I built out into suburbs.  Sorry, I'm mixing up cause and effect.  I didn't mean to imply that I had a static-sized region while testing.  But I don't mean to discount that it has helped in making more desirable traffic patterns so I can focus on aesthetics and development, rather than worry if the Sims are jamming the "wrong" roadway.

Yes, the transportation system in many city tiles are essentially "unchanged", since I build infrastructure before unpausing for the first time.  The region I'm creating is very much lane-deficient, has a lack of alternative routes and abundant bottlenecks.  The single avenue that serves my eastern suburbs is already red (9000 vehicles westbound, on medium) and this connects to the only freeway through town (dark orange at 10000 westbound).  Eastbound traffic will be even worse when I finally create them.  I will remove the Residential Halver, and see how the simulator handles twice as much traffic as before.  And congratulations, you've figured out the main plot of a mayor diary I'm writing about this region!

Now, to everyone, here are the pictures:

Draw paths:
(http://img126.imageshack.us/img126/29/drawpathsnr2.jpg)

Route query; there are only about 30 "local" commuters on this street:
(http://img123.imageshack.us/img123/7351/routequery1ni2.jpg)

Querying the offramp:
(http://img117.imageshack.us/img117/8973/routequery2yh3.jpg)

I've built many practice replicas of my neighborhood and this issue does seem to always happen.  Automata is set to low, for performance.

Condemned some houses to extend the offramp:
(http://img116.imageshack.us/img116/1185/routequery3vb6.jpg)

I've tested both scenarios for 5 years each, and yes I've started to notice the behavior in the traffic volume graph.
Title: Re: A Next Generation Traffic Simulator
Post by: Tarkus on December 23, 2008, 09:18:19 PM
sumwonyuno, thanks for posting the DrawPaths pics!  It does indeed appear there is something up with the pathing on the OWR Diagonal/Street intersection that's causing your problem.

-Alex (Tarkus)
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 25, 2008, 03:42:32 AM
I can't reliably use population or job numbers in many city tiles, in the aftermath of removing the Residential Halver.  There has been a predictable wave of abandonment.  According to the graphs, populations have "doubled".  As for traffic, overall congestion is somewhat worse and more parallel roadways are being heavily used.  Car usage has doubled, and mass transit use has risen several fold.

The following isn't a problem, it's just something interesting.

The biggest wow is certainly pedestrian use.  It's not that it's out of line in relation with mass transit in the graphs.  The phenomenon takes place in the route queries.  It's not that I don't want Sims commuting to the next tile.  In my most dense city tiles, Sims are going through neighbor connections by walking.  Not by the hundreds, not by the thousands, but by tens of thousands (the biggest is almost 40,000 on one avenue).  Many do walk directly from their homes.  That's not all.  It's that many of them were previously on buses, got off at a stop somewhat close to the neighbor connection and walked the rest of the way.  Yes, there are stops right next to the connections.  They aren't transferring off en masse there, though some are.  Also, the Sims aren't "shortcutting" by walking in and out of bus stops along the way.  In virtually all other simulators I've used, Sims have not had this behavior, they would have stayed on MT.  The walking is definitely happens with congested connections.  In city tiles that don't have bus stops, there are only a few dozen walkers to neighbor connections from houses right next to it. 

I think it's definitely is due to features you have described about your simulator.
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 25, 2008, 04:36:01 AM
Thousands of Sims crossing the border by walking - that's fascinating.  I've never seen or heard of anything like it.  But looking at the simulator's internal numbers, I can see why it's happening.  At maximum congestion, the buses are traveling slower than the Sims can walk.  (This certainly happens in real life sometimes.)  So the Sims get off the bus and walk simply because it's faster.  I think I understand why this happens only near borders.  The border is considered a job destination, and maximum walking speed is far below maximum bus speed.  Only when the Sims get relatively near the border is it clear to the simulator that walking is the fastest way there, and so that's where they get off the bus.  That's what I think is happening.

As for the fallout from removing the Residential Halver, unfortunately, this is to be expected.  But it can be recovered from by creating more jobs where necessary and also by beefing up the transportation infrastructure and possibly using a higher capacity version of the simulator as well.  If you do this, the end result should be a better functioning region than you had when using the Residential Halver - it may just take a while.  And when your congestion drops below the maximum, your Sims should stay on the bus for those border crossings.
Title: Re: A Next Generation Traffic Simulator
Post by: b22rian on December 25, 2008, 06:42:18 AM
hi.. Ive been following the thread with a lot of interest lately..
That is quite interesting what sumwonyuno had to say about the pedestrians and buses..

Actually I will share with you one of the things i enjoy most about sim Z, somewhat related to it..
But one of the best changes for me in using sim z is that bus usage is now down to a more realistic levels
in most cities about down to 8: 1 ratio to cars.. Which i think is still prolly higher than most people have
using sim Z..But before the number of buses i had roaming the streets and roads was a bit out of hand..
I think the usage was far too high.. Now some of this may have been because I had gotten a bit carried
away .. using too many bus stops..But without doing anything on my own Sim Z has gotten the bus usage down
to a more sensible number i feel.. I also love how buses now count toward congestion levels as they should..
This is the other change for me i think is great..

Thanks, Brian
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 25, 2008, 03:29:27 PM
I had been wondering for a while when you had stated in your beta explanation post about a relationship between transit use and capacity level (using Ultra to simulate low transit use).  It makes complete sense now.  I'll try bumping it up to High capacity; at the moment, I doubt I need to use Ultra.
Title: Re: A Next Generation Traffic Simulator
Post by: b22rian on December 25, 2008, 06:16:53 PM
I had been wondering for a while when you had stated in your beta explanation post about a relationship between transit use and capacity level (using Ultra to simulate low transit use).  It makes complete sense now.  I'll try bumping it up to High capacity; at the moment, I doubt I need to use Ultra.

yup. you need to find that setting that is challenging to you, but not so hard you feel its impossible or frustrating..
Keep us posted how your doing.. its nice to hear from you..,

Thanks, Brian
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 25, 2008, 11:22:04 PM
sumwonyuno, I've been thinking more about your city, and I think I can explain a little more about what's going on in a way that may be helpful for deciding what to do next.

I think as you and Brian have both gathered, the reason you don't see pedestrian situations like the one you've described in other simulators is due to the fact that buses count as ordinary traffic in Simulator Z.  For any other simulator, the natural thing to do would be to pile Sims into buses - all 40,000 of them - because that doesn't increase congestion at all.

But Simulator Z acts differently, as you know.  What has to be going on for 40,000 pedestrians to be streaming across the border?  First of all, your avenue has to be at maximum congestion.  This means that at the Medium setting you're using, it has to carry at least 250% of its nominal capacity, which is 4000.  (With this sort of border situation, I'm assuming that essentially all the traffic is moving in only one direction for each commute period.)  So 250% of 4000 is 10,000, which means that there are at least 10,000 car and bus passengers traveling on the avenue.  Add to this the 40,000 who got off the bus (since the number walking directly from their houses is negligible), and you get an initial 50,000 Sims trying to use one side of that avenue.  That's 1250% of the avenue's nominal capacity.  No wonder you've got problems!  No real road can hold much more than about 300% of its nominal capacity.  So the simulator looks at this situation, where the Sims are all originally using buses and cars, and tries to figure out what it can do to reduce the congestion.  It can't do anything about the Sims in cars (presumably other routes nearby are also clogged), so they're stuck there.  But the Sims on buses can change to any other form of mass transit.  Unfortunately, there are no rails anywhere nearby.  But as I mentioned before, walking is now faster than riding the bus, and pedestrians don't contribute to congestion.  (Normally this makes sense, as there are few enough of them to stay on the sidewalk.)  So the simulator has the Sims get off the buses and walk, thereby both reducing congestion and speeding up the Sims' trips.

Understanding this, you can see why using a higher capacity version of the simulator and doing nothing else will not solve the problem completely.  For example, with the High version of the simulator, avenues have a capacity of 6000 Sims per side, which means that 250% congestion occurs at 15,000 instead of 10,000.  So switching to the High version of the simulator will probably reduce your border pedestrian traffic only from 40,000 to 35,000.  The Ultra simulator, with its capacity of 12,000 per avenue tile, reaches maximum congestion at 30,000, which means you'll still have about 20,000 Sims walking to the border.  That's why in my earlier message, I recommended "beefing up the transportation infrastructure and possibly using a higher capacity version of the simulator as well."  A single rail line in the right place, even with the Medium simulator, will do wonders for this problem.  If you wanted to be very discreet about this and not change your landscape, you could put a single subway line under your avenue.  In the Medium version simulator, it would have a capacity of 15,000 Sims.  But even at maximum congestion, the subway speed is still faster than that of an uncongested bus line (though much slower than an uncongested subway).  So all your would-be pedestrians would now take the subway, and even though they'd be crammed in like sardines, it would still be the fastest way to go.

Hope this is helpful...
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 26, 2008, 04:31:45 AM
I have said it was just something interesting, not a problem.  Once in the neighboring city tile, the Sims do get back onto buses and onto their destinations.

Nevertheless, I think I've found a missing piece of this puzzle that explains it all.

[Salt Lake Boulevard]
(http://img224.imageshack.us/img224/1236/saltlakeblvdat9.jpg)

Scratch what I said earlier, I've chosen Ultra to have the least congestion as possible, which according to our hypothesis, in turn should encourage car use and limit bus and pedestrian use.  I was shocked to find that pedestrian behavior was roughly the same.  Both congestion and traffic views had changed to barely have anything above yellow (only a short slice of a bus route in the middle of highrises, 50+ tiles away from the connection, was red).  I moved on, since the Sims were indeed transferring to buses in the neighbor city tile.

[Pali Highway]
(http://img116.imageshack.us/img116/4678/palihwylf5.jpg)

Next, I went into another tile that previously had no bus service.  It did have a handful of connection walkers.  I added a few bus stops and it stabilized at 3000 Sims walking to the (only) neighbor connection.  I did save the city tile and I went into my Downtown to place bus stops to "catch" those connection walkers.  I looked at the edges of my Downtown to find any more instances. 

[Downtown edge]
(http://img117.imageshack.us/img117/6559/epiphanyvp7.jpg)

There is the King & Beretania Street Couplet.  Beretania is one-way westbound, while King is one-way eastbound.  I was wondering why had the Sims abandoned their buses in order to go to the next city tile.  Wouldn't it be faster for the Sims to keep taking the bus on King Street when it was less congested?  Then it hit me.  Beretania was closer to homes.

The general layout for many of my linearly-laid city tiles have major east-west arteries.  Residential dominates towards the mountains (north) while commercial and industry take up whatever is left toward the shore (south).  So, westbound lanes were closer to homes, including sidewalks.  According to the simulator, walking the westbound half of streets was much more convenient.

Evidence can be seen in the first picture.  I had queried each highrise on Salt Lake Boulevard (the avenue + oneways) and they all chose walking.  Parallel side streets were "fine".  First, if they all had chosen cars, it would have caused additional congestion on Salt Lake Blvd.  Whether they chose cars or buses, they would have to make a U-turn at the next stop light at the west in order to go east, further increasing commute times.  The simulator had deemed walking as the most optimal.

The Pali Hwy picture should have also hinted at this behavior.  The 1145 pedestrians on the northbound lanes heading south to the connection did this because this sidewalk was closer to their homes.  Most of the pedestrians on the other side were sent off walking because if they had stayed on the bus, it would have added congestion to the southbound lanes.

In the last picture, those 17000 pedestrians would have really jammed up King Street if they had been placed on buses.
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 26, 2008, 03:22:56 PM
I think you're getting the hang of how the simulator works, and I agree, the Ultra version seems most appropriate for your cities, as it is often the best version for cities with little or no rapid transit.  Having some congestion ("barely above yellow") seems just about right for rush hour in cities such as these.

The one mystery that was left here is those 36,454 pedestrians in the first picture.  I think I can explain this.  It has to do with the fact that different parts of the simulator work at different rates.  The first time the simulator is run, it notices the extra capacity, and your congestion map changes significantly to reflect that.  But as I mentioned in an earlier post, actual changes in commuting patterns usually take years to complete, due to the anti-herding effect.  So over a period of years, that pedestrian figure should gradually drop.

Meanwhile, there's just one other point I'd like to clear up:

Quote
I've chosen Ultra to have the least congestion as possible, which according to our hypothesis, in turn should encourage car use and limit bus and pedestrian use.

You're partially correct here, but what upgrading to a higher capacity simulator does is highly dependent on how much congestion there is in a city as well as what transportation types are available.  In your cities, there's no mass transit that's faster than cars, so car usage should already be at its maximum, and moving to the Ultra simulator shouldn't change it.  The same is largely true with buses, with the exception that the reduced congestion will allow thousands of pedestrians to stay on buses instead of walking.  So to summarize, car usage should be about the same, bus usage should increase somewhat, and pedestrian mileage should decrease.

I really appreciate all the detail you've posted about your cities here, as it's quite different from anything I've personally tried, both in layout and in transportation usage.  You've helped to verify that the simulator works properly in a very wide variety of circumstances.  Thanks! :)
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on December 29, 2008, 04:32:35 PM
I think I will settle on High for my region.  Medium and Low have too low capacity.  Ultra just has too much capacity.  With roads at 12000 for 100% usage, commuters have undesirable traffic patterns (e.g. they're all comfortable going to a road's neighbor connection, rather than a parallel highway's because it's shorter and has so much capacity).  There is a lack of congestion :P and bus ridership, which are the opposite of what I intend to simulate.

Now, I do have a question.  I assume RTMT is compatible with this, since you are on the team.  Which capacity level should I be using?

[edited to correct the names of the simulators]
Title: Re: A Next Generation Traffic Simulator
Post by: z on December 29, 2008, 05:05:27 PM
Quote
Ultra just has too much capacity.

Well, I didn't call it Ultra for nothing.  $%Grinno$%  What you say makes sense, though; my intention was that Ultra should only be needed for very high density cities with little mass transport, and so I'm glad that High works for you, since your cities don't appear to be all that dense.  (I think what you are calling Hard is High and what you are calling Easy is Low, although these are the opposite of the actual correlations.)  I noticed your connection between congestion and bus ridership; this makes sense, as in RL, the more congested the roads get, the more likely people are to take public transit.

As for RTMT, you should install it using any capacity; then you should use the RTMT file included with the Simulator Z distribution to replace the equivalent file in the standard RTMT distribution.  This new file is designed for regions that ever anticipate having simulator capacities higher than Low, and has been updated to better support Simulator Z, though it's designed to work with any traffic simulator.  It will be one of the two standard capacity files in the next RTMT release.  Although it's easy to switch simulators back and forth, the RTMT files containing capacities are a different matter (as are all other transit stations).  Although you can change the RTMT capacity file in mid-game, this doesn't change the capacity of existing stations, only new ones.
Title: Re: A Next Generation Traffic Simulator
Post by: redraider147 on January 14, 2009, 02:24:05 PM
so noticed a massive difference (possibly a bug?) between the alpha release I was using and the beta i just started using.. It seems that the congestion on all my roads and streets and avenues etc, is much higher, while the volume is now much lower. also, it seems that my sims do not want to drive to work any more. My mass transit is ridiculously high...and the people who are taking it are the wealthy sims. the poor sims are driving. this seems to go against the natural build of RL and the game. I am wondering as to what might be causing this.

A side note, the abandonment problems we thought might be related to a conflict between the Alpha Release the CAM have virtually disappeared. and while my congestion is much higher while volume is lower, commute times are down. also it appears that my work on the express tracks with elrail and subway and GLR no longer works as the sims tend to overload the local trains even though they are going well down the line and actually getting off at an express stop. i guess it seems that the sims do not like the long rides without stops on the elrail/subway. i'll keep researching this and see if anything changes it.
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 14, 2009, 03:02:23 PM
It sound to me like you've installed the Park and Ride version by mistake.  Does your simulator file contain "_ZP_" in its name?  That's the Park and Ride version.  You want to make sure that your version just contains "_Z_" in its name.

Otherwise this does not sound like Simulator Z at all.  I would first want to rule out the hidden presence of another simulator.  The best way to do this is to remove Simulator Z from your Plugins directory and run the game for a while.  If things don't change radically within a few years, then you've got another simulator overriding Simulator Z and you've got to find it.

Otherwise, we'll have to dig deeper.  I'd start by asking you to tell me the name of the simulator file you installed.
Title: Re: A Next Generation Traffic Simulator
Post by: redraider147 on January 14, 2009, 03:21:55 PM
the only simulator i've been running for quite some time is the alpha of z. and the ZP is not in the file. i'm not sure...maybe still conflicting with the CAM, but in a different way?
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 14, 2009, 03:24:41 PM
I don't think so.  What is the name of the current simulator file you're using?
Title: Re: A Next Generation Traffic Simulator
Post by: redraider147 on January 14, 2009, 03:38:37 PM
NetworkAddonMod_Traffic_Plugin_Z_High.dat and NetworkAddonMod_Volume_Data_View_Z_High.dat

Formerly with the alpha release, i was using Tarkus' Congestion View...would that have anything to do with this? Currently I do not have a congestion view mod installed unless there is one now included with z. which would result in me using the maxis congestion view and could be distorting my findings. I still am not sure about why my poor sims are driving and my wealthy sims are taking mass transit...
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 14, 2009, 06:28:36 PM
Formerly with the alpha release, i was using Tarkus' Congestion View...would that have anything to do with this?

Though I'm not really familiar with Tarkus' Congestion View, I don't think it's involved in your problem.

Quote
Currently I do not have a congestion view mod installed unless there is one now included with z. which would result in me using the maxis congestion view and could be distorting my findings. I still am not sure about why my poor sims are driving and my wealthy sims are taking mass transit...

Simulator Z does not include a Traffic Congestion View.  The Maxis Traffic Congestion View works fine, and I recommend its use with Simulator Z.  As for your wealthy Sims, under normal circumstances, 80% of them will prefer to drive, which is the same percentage used in other simulators.  However, if there is severe traffic congestion, as you report, they may move to mass transit.

I think I see what's happening here, based on the simulator you just installed.  All the Alpha releases of Simulator Z (with the exception of the special "MT" version of Alpha 4) have the network capacities that are now used in the Ultra version of Simulator Z.  The High version, which you installed has half these capacities.  So all your network capacities were suddenly cut in half.  Additionally, if your previous version was earlier than Alpha 4, buses didn't count toward congestion; now they do.  Putting these together, it's very understandable that you're seeing what you describe.

The beta version, though (which has actually become the release version), has a better pathfinder and in general is more heavily optimized than the alpha versions.  So for most people, switching from the alpha version to the High version of the current simulator should work.  However, the internal simulator takes a while to adjust things.  How long have you run the new simulator?  It usually takes about five years for the new simulator to completely reorganize traffic patterns into their most optimal form.  You can tell this has happened when the lines in the Traffic Volume Graph stabilize for at least a year.

If you have run the new simulator for at least five years, and the lines in the Traffic Volume Graph have stabilized and you still have problems, this means that your city is built in such a way that it needs the higher capacities it was using before, and you should switch to the Ultra versions of the simulator and Traffic Volume View.  This should definitely fix your problems.  Please try these approaches in the order I have listed them, and let me know how it works out.
Title: Re: A Next Generation Traffic Simulator
Post by: gn_leugim on January 15, 2009, 01:37:02 PM
Hi there..

I've download the new NAM today, and tried your simulator.. I installed the medium one.. when I started on of my cities it happened something weird.. the city was 25k pop.. and suddenly the population dropped to 10k..  :o %confuso 15k people left town as they didn't have jobs.. something that they always had.. the traffic volume graph showed a drop of all types of traffic after 3 months running the game.. I repeated the experience, this time without moving a thing.. just to see what happens.. the same.. about 15k became jobless without reason.. the only thing I've changed from the last time I entered that city was NAM, in particularly the traffic simulator.. Any guess of what happened?  :'( :'(
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 15, 2009, 02:14:58 PM
When you change traffic simulators, especially to one that is very different from your old one, you will always get the dropoff of traffic you mentioned, although when it comes depends on the particular city.  This is because the new simulator has to recalculate routes for your Sims, and in the mean time, some of them don't have any routes to work.  In most cities, the effect is small enough not to have any effect on the population, but in some cities, such as yours, it may.  Fortunately, this is a temporary phenomenon.  If you keep running the simulator, you will notice that after a number of months your traffic will suddenly rebound to its previous level or close to it, and your Sims will quickly move back in.  Over the next few years, traffic patterns will gradually change to fully accomodate the new simulator.  At the end of this time, your traffic patterns should be much better than before you switched simulators, and your city growth should be quite healthy.  Try running your city a few years (you might want to save a copy first) and let me know what happens.
Title: Re: A Next Generation Traffic Simulator
Post by: gn_leugim on January 15, 2009, 02:38:21 PM
ok then... I'll try to run the city for some while.. I did it too for other city, and in that one no change was notice  :-\

I'll soon give news  "$Deal"$
Title: Re: A Next Generation Traffic Simulator
Post by: b22rian on January 15, 2009, 03:48:57 PM
ok then... I'll try to run the city for some while.. I did it too for other city, and in that one no change was notice  :-\

I'll soon give news  "$Deal"$

Hello Gn leugim.. Please run your cities for at least 6 game years.. before reporting back to us..
                       Even if you feel you have solved the issue..we would like to hear back from you..

Thanks, Brian
Title: Re: A Next Generation Traffic Simulator
Post by: gn_leugim on January 15, 2009, 04:33:02 PM
well, here is the result.. I run the city for about 6 years..without doing anything.. just let it run.. no big change =1
first, let me show city, Zone map:

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057730.jpg)

and Trafic map:

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057786.jpg)

here we can see the initial step, where most of the people stops commuting..

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-20Jul301232056710.jpg)

and here are the results after 6 years.. 

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057538.jpg)

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057561.jpg)

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057607.jpg)

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-17Mar361232057638.jpg)

So, what do you think?  %confuso

I'll cya tomorrow as I have to go to bed now  /wrrd%& I have test tomorrow  %bur2$ ()lurker()
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on January 15, 2009, 10:57:59 PM
I've downloaded the new NAM + RHW and reinstalled the CAM, and I've just been overwhelmed and giddy :D, therefore I haven't done any sort of testing of my current region yet.

gn_leugim this does sound like what I went through.  Your city isn't large, doesn't seem that complex and assuming you have a decent configuration, the simulator should have reached an equilibrium by 6 years.  Is this the only city tile with jobs?  From my experience in using Simulator Z, no-jobs zots and abandonment are caused by 1. the simulator going so fast they indeed go over the 6-month job-hunting limit when commutes are recalculated and 2. there really are a lack of suitable jobs.  I notice in your pictures that the number of R$ sims going down, while R$$ and R$$$ aren't.  I can't tell the exact distribution of the jobs, but I can guess that there might have been too much R$.

Also I've noticed that the no-road-access zot sometimes appears in newly-built homes (groups of ~ 3-6) that do have road access.   In the query it says abandoned due to commute time.  It's probably related to the 6-month limit, but it just happens when the R zones are developed.  Everything else around will act "normal" (find jobs or abandon).
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 16, 2009, 01:00:21 AM
gn_leugim:  Thanks for posting all those pictures!  They are extremely helpful in seeing what's going on.  And the good news is that I think you're in better shape than it appears at first.

I mentioned before that a traffic drop is normal when switching simulators.  But usually it's no more than about 30%, and there's no effect on the city population.  Your traffic drop is about 60%, way higher than I've seen before, and this is what's causing the population drop.  Since the Sims actually leave town, the traffic doesn't rebound in a few months the way it usually does.

So what's causing this unusually massive traffic drop?  It's not Simulator Z; switching to any very different simulator would have the same effect.  Instead, there are some unique characteristics about your city that are involved here.  It's hard to tell for sure with the current amount of data, but I would guess that it's a combination of your city's small size, which makes it very vulnerable to fluctuations, plus the fact that a large percentage of your jobs are connected to the island where your residences are by a single bridge.  This means that the traffic simulator must route a lot of Sims over that bridge, but the internal Maxis routing code limits the rate at which Sims can be added to a single route.  So when routes are recalculated when the simulators are switched, the bridge acts as a bottleneck to the whole process.  Evidence for this can be found in the sharp drop in commute time, which would be expected if the bridge usage has declined significantly.

This doesn't mean that Simulator Z won't work here; it simply means that since your traffic decline was so deep, it will take longer than usual for things to recover completely.  There are some encouraging signs here.  On your Population and Jobs graph, your middle-income Sims' population has increased significantly since the simulator switch, even though the overall population has declined.  So you're getting a better population mix here; this is important if you want anything other than low-wealth jobs.  Industrial jobs are gradually rising.  But most important is the population on the RCI Totals graph.  It started a little over 25,000 and dropped down to 13,000.  But currently it's at 20,000, which is the highest it's been since the drop and almost 80% of its previous high, and it's headed almost straight up.  It looks to me like things are already improving here.  But due to the fact that the initial traffic drop was so sharp and you lost so many Sims, it's hard to say exactly how long it will take to surpass your old high.  Yet that straight spike up at the end of your population graph is very encouraging; that's the best upward spike you have in your whole graph.

So I would simply recommend running your city longer.  Run it another fifteen years if you have to, though I don't think it will take anywhere near that long to restore your city to full health.  Please let me know what happens.
Title: Re: A Next Generation Traffic Simulator
Post by: sumwonyuno on January 16, 2009, 04:35:59 AM
First impressions of the new NAM Jan 09:

Wow, z, did you do anything to the simulator before you gave it to be included in the NAM?  I need to thank you again that now commute patterns are the most real-life-like yet.

I reinstalled the CAM, and I am able to manage my abandonment issues in the city tiles I've updated so far.  This has had the effect of adding even more residents and increasing traffic volumes.

First thing I noticed w/ the new NAM was the congestion view was much more checkered.  Due to the intersection effects, tiles around intersections became red.  As I ran the simulator for no less than 10 years in each tile, traffic became even worse.  This is not a bad thing, because the Sims are commuting in much more expected patterns.  The percentages among walking, bus and car are generally about those in real life.  I'm getting to the point of High doesn't seem like it has enough capacity.

In the city tile picture with 26000 connection walkers, before I had installed the NAM today, it was past 50000 on the westbound-lanes' sidewalk, then with about 9000 cars, and a few hundred on buses on the eastbound lanes.  Today with the new NAM, almost 29000 cars are going eastbound, almost 26000 are still walking eastbound on the westbound side, and no buses from the boulevard.  Even on Ultra this would be over-capacity.  At this moment, the commute time graph reports under 3.5 minutes(?) for this city tile.  However, I actually have too much highrises (and therefore commuters) in this city tile.  Once I fix that, I expect the traffic volumes to be lower, congestion to be lower, and get into a situation where there isn't a mass of connection walkers.

In my eastern suburbs, on the east edge of one city tile, the single avenue is carrying over 19000 cars going westbound.  The avenue transitions to a highway which ultimately carries over 25000 westbound at the western edge of the city tile.  Also on the western edge are 3 road connections with about 6000 cars and few hundred buses each.  Commute time graph reports over 140  :shocked2:.  I haven't updated my downtown tiles yet, but I expect that I'll get into situations that will warrant a switch to Ultra.

z, you said an intriguing thing about gn_leugim's situation with the bridge:  Maxis limits the rate trips are added to a single route.  I'm thinking this could also relate to my region where there are such few thoroughfares and options to handle a population with high density.
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 16, 2009, 05:40:14 AM
The version of Simulator Z in the NAM is the unmodified Beta 1 version.  I simply upgraded it to the release version when nobody could find any bugs in it.  However, Simulator Z does interact strongly with the CAM, so if you manage your CAM better, Simulator Z will automatically work better as well.

From the ReadMe included with the NAM:

Quote
Which simulator version is appropriate for a particular city depends primarily on two things: the population of the city, and the amount of rapid transit (rails) available. Less capacity is needed for lower population cities, but less capacity is also required for cities with a lot of rapid transit.

As you have no rapid transit, you will need a higher capacity simulator than the same city with rapid transit.  Also, intercity commuting raises capacity requirements, as you have the same Sims counting toward traffic in multiple cities.  The Ultra version of Simulator Z was originally designed to handle the higher capacity requirements of intercity commuting.  But if you combine extensive intercity commuting with a lack of rails, you're going to get significant congestion even with the Ultra version.  That situation is a lot like Los Angeles, which has a very large number of expressways, but the worst traffic congestion in the country.

Due to a bug in the game, it's impossible to get the Commute Time numbers to be completely accurate.  And the numbers of one city can't be compared to the numbers of another.  Instead, you just want to look for trends in the graph.

Quote
z, you said an intriguing thing about gn_leugim's situation with the bridge:  Maxis limits the rate trips are added to a single route.  I'm thinking this could also relate to my region where there are such few thoroughfares and options to handle a population with high density.

This effect is generally not visible during normal play, where traffic patterns change gradually.  Normally, you see it only when switching simulators.  I'm rather sure it's not related to your situation; a simple lack of rapid transit is enough to explain what you're seeing.
Title: Re: A Next Generation Traffic Simulator
Post by: gn_leugim on January 16, 2009, 12:52:05 PM
So, if I understood, if I run the city a even more time, I'll get the situation normalize?  :-\ I'll try to run further then.. I'l give simulator z a last chance  :D (joking ^^)

i'll report soon..

EDIT:

I found the reason for all this.. is about NAM and not the simulator.. all started when I built a new bridge.. all people became happy with jobs.. but then I notice something weird.. most of the people that crossed the new bridge returned to the island through the old bridge and then stop at his work, on the island.. weird I thought.. then I remember to type: DrawPath on the console.. and I found this:

(http://i93.photobucket.com/albums/l79/gn_leugim/Escarpada-4Mar301232142140.png)

this roundabout is a major artery.. thought it flows all the traffic that goes from the most of the island to the bridge..
with the transition to NAM the roundabout lost his paths (or something like that) so, I restarted (for the 10th time lol) the city, and the first thing I did was to rebuild that roundabout.. and voila.. it is growing again, all working fine  :)) &hlp &hlp

I'll report this to the NAM issues thread.. I think that this could interest them :)
Title: RTMT Patch for Simulator Z Users
Post by: z on January 17, 2009, 03:49:43 AM
With the formal incorporation of Simulator Z into the new NAM, a more complete RTMT patch has been constructed and released.  RTMT users should read this post (http://sc4devotion.com/forums/index.php?topic=5717.msg215500#msg215500) for details and access to the patch.
Title: Re: A Next Generation Traffic Simulator
Post by: z on January 18, 2009, 08:46:47 PM
There is now a dedicated support thread for Simulator Z.  If you have questions about Simulator Z, or need help in using it, please post in the NAM Traffic Simulator Z Help (http://sc4devotion.com/forums/index.php?topic=6812.0) thread.  Thanks! :)
Title: Re: Traffic Simulator Z Development
Post by: z on March 24, 2009, 04:51:17 AM
Although the main work on Traffic Simulator Z is finished, from time to time there will be some development.  As this is the original Simulator Z development thread, it seems to make sense to continue discussions and announcements of such development here.  I have renamed this thread to reflect this focus.  Support issues will continue to be addressed in the NAM Traffic Simulator Z Help (http://sc4devotion.com/forums/index.php?topic=6812.0) thread.

The issue I would like to address right now is street capacities, and especially in the context of SAM streets.  Simulator Z has been out long enough now that many people have experience using it with SAM, and streets in general.  Do the capacities of the various levels of the simulator seem about right for these streets?  Or do people feel they need to be adjusted one way or another?  Any feedback you can furnish will be helpful for the next release of Simulator Z.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on March 25, 2009, 12:08:31 PM
Im still very happy with the current Capacity level for streets..
And I think its right on the money still..,

Thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: z on April 17, 2009, 03:00:28 AM
Currently, the following minor updates are planned for the next release of Simulator Z, which will be V1.1:


Due to the vehicle pollution controls already in place in Simulator Z, monorail pollution will range from undetectable to nearly so.  This has already been tested.

The el rail speed is currently set artificially slightly higher than the subway speed to encourage use of the el rail trains.  This has proven to be no longer necessary, as experience has shown that far fewer subway lines are required in Simulator Z than in previous simulators in order to get good traffic flow.

The following modifications are being considered for V1.1:


Currently, Simulator Z has a monthly subway tile cost of §1.20, which is four times as much as all the other traffic simulators.  No one has complained about this, and it is still fairly easy to put a subway under every road in a prosperous city.  As no real world city could afford to do this, it is obvious that this cost is still way too low.  On the other hand, I don't want to break a lot of existing cities by raising it up to where it should logically be.  So I'm thinking about a relatively small increase here.

Feedback on the subway monthly tile cost increase from Simulator Z users would be greatly appreciated.  How much do you think this increase should be?  Also, feedback on any of the other changes mentioned above is welcome.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on April 18, 2009, 08:02:14 PM
Im ok with doubling the sub way cost...
But no higher than that i think..

Thanks, brian

Title: Re: Traffic Simulator Z Development/ Bus usages..
Post by: b22rian on April 19, 2009, 06:35:17 AM
Hi,

Since I started using traffic Sim Z, i wanted to mention im very pleased what it has done for more
realistic bus usages for me..  Back when i was using some of the other traffic sims i was getting  (in
some cities )..usages well over 40 %.. which i felt was getting a little out of hand.. Now my bus usages are
down to a more realistic level of 10 - 15 % in cities where im making good use of Bus stops..
I also really like how buses now count toward traffic totals in terms of calculating traffic congestion,
where as before traffic sim Z came along that wasnt the case..
How do others feel about their bus usage figures since using traffic sim z ?

Thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: mike3775 on April 19, 2009, 08:02:38 AM
I'm happy that my sims actually take the buses now.  I used to plop craploads of bus stops and they would never be used, now they actually use almost all the stops I place

As far as subway price goes, like Brian stated, a doubling would be ok, but not more than that.
Title: Re: Traffic Simulator Z Development
Post by: z on April 22, 2009, 01:01:40 AM
A version of Simulator Z now exists for the Bullet Train Mod (BTM).  This version of the simulator has been modified so that the BTM has a speed of 400 kph, instead of the 250 kph speed which results when the standard version of Simulator Z is used with the BTM.  The higher speed has been observed to result in usage of the BTM 20 times greater than the standard monorail speed.  A zip file containing the complete set of Simulator Z versions, modified for use with the BTM, is attached to this post.

If you wish to use this modified traffic simulator, simply download the zip file and replace your current traffic simulator with the BTM version.  If you are already using Simulator Z, the names will be identical except for the extra "BTM_" in the modified simulator.  The main effects of this modified simulator are that you will get increased use of the bullet train.  I would be interested in hearing additional details from those people who use this modified simulator.

If you use this modified simulator along with the HSR patch that allows both BTM and HSR at the same time, then both will have the speed of 400 kph.  This is unavoidable, as they both use the same underlying network.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on April 22, 2009, 11:13:42 AM
Ok Z ,here are the results of my 6 year test using the bullet trains at 400 k/h as you suggested....

city Population  1280 K

Bullet train    at   250 K / H                 At  400 K / H

   Monorail usages   115 K                    135 K

  other transport types..

    Car                 400 K                     395 K
    Subway           305 K                     300  K
    train                215 K                     220 K
    Bus                    80 K                      90 K

Result :  Using 400 K/ H as the bullet Train speed there was an increase in usage of about 20 K
            those who used the monorail/ bullet train network over the old speed of 250 K/ H..

Thanks, Brian

Title: Re: Traffic Simulator Z Development
Post by: mike3775 on April 22, 2009, 11:29:53 AM
stupid question time, but how would I place this update into my NAM folder when I used the DAT packer?
Title: Re: Traffic Simulator Z Development
Post by: z on April 22, 2009, 02:46:38 PM
It is highly recommended that you don't datpack your NAM folder for reasons such as this.  Although there are workarounds, I'd strongly suggest redoing your datpacking while leaving out the NAM folder.  Doing this should not make a noticeable difference in your load time.
Title: Re: Traffic Simulator Z Development
Post by: mike3775 on April 22, 2009, 05:29:36 PM
Ahh ok.  Thanks, will redo the Dat packing right away then

Thanks
Title: Re: Traffic Simulator Z Development
Post by: z on April 23, 2009, 04:48:43 AM
Ok Z ,here are the results of my 6 year test using the bullet trains at 400 k/h as you suggested....

One thing I've noticed during these tests is that the biggest gains in usage come in those cities where usage is initially the lowest.  Your cities have always had about the highest monorail usage that I've seen, so it's not surprising that your gains are much less than the others (although to be honest, they still are surprisingly low).  Could you please post a picture of the minimap of your Traffic Volume View, with the view set to "monorail"?  Thanks!

BTW, with regard to the subway costs, I was thinking of a maximum increase of 50%.  Based on what I've seen, that shouldn't be a problem.  If anyone thinks it is, please post here.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on April 23, 2009, 06:06:36 AM
although the monorail usages are high in a few parts of my city, the system was never fully completed the way it
should have been . In the city I tested , the monorail is really only used in 3 smaller areas of the city ( we know
that to fully optimize monorail systems there  best used for longer distances , utilizing there greater speeds..)
I think the reason for the modest increase in usage only, is because the system is already pretty optimized in the
3 small areas where the monorail system is used..

  As you well know Z, Traffic is very complex in the game, and usually many factors are involved, so no 1 test is
ever going to tell you a great deal.. We need more tests really to garner any useful results..from this..


Thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: z on April 23, 2009, 11:54:55 AM
I think the reason for the modest increase in usage only, is because the system is already pretty optimized in the
3 small areas where the monorail system is used..

Yes, that was my guess as well.  And if it's only used in a few small areas, it's much easier to get its usage fully optimized.  What the higher speed limit does is to draw Sims in from farther away.  But that only makes sense if they can travel a fair distance on the monorail/BTM (which are both designed to be long-distance travel types, as you noted).  So this indeed would explain why you're not seeing much increase.

On a related note, I realized that fixing monorails to contribute to and be affected by traffic congestion will actually make them work better for most people!  Congestion only happens when networks are over capacity, which rarely happens for monorails and HSR in Simulator Z.  The way all traffic simulators compatible with RHW work, speeds actually increase above the nominal the farther below capacity the network is.  And increased speeds mean increased usage.  I've done some tests, and this proposed change should result in substantially increased usage in those parts of the monorail/HSR/BTM networks that are used the least.
Title: Simulator Z v1.1
Post by: z on April 25, 2009, 08:09:42 PM
I've now created and tested version 1.1 of Simulator Z.  It's ready for general use, and should be available in the next NAM update.  Until then, you can get it here, at the bottom of this post.  It includes the modifications described in the first three points from the first post on this page, along with a 50% increase in monthly subway operating costs.  If you use monorail or HSR, and still have lower than desired volumes with these travel types, I would strongly suggest giving this simulator a try.  In my tests, the average monrail/HSR line more than doubled in usage with this new version of the simulator.

The zip file contains all eight standard versions of the simulator; you should install only one of them.  The versions containing "_Z_" in their names are the regular versions of the simulator, while the versions containing "_ZP_" are the Park & Ride versions.
Title: Re: Traffic Simulator Z Development
Post by: z on May 04, 2009, 03:47:34 AM
After doing extensive testing of the new RTMT SAM stations (which have not yet been released), I made a minor modification to Simulator Z that increases the effectiveness of buses on streets.  Nothing else was changed.  The new version of Simulator Z can be found at the bottom of the preceding post.
Title: Re: Traffic Simulator Z Development
Post by: z on May 28, 2009, 12:28:34 AM
I would like to increase the accuracy of Simulator Z a little more by tuning one specific parameter a bit more precisely.  To do this, I will have to have a fair amount of data.  If you are willing to run some tests using Simulator Z (any version), if you know the basics of Ilive's Reader well enough to change a single parameter, and if you have a city with at least five monorail, HSR, or BTM stations (in any combination) that have decent usage, please send me a PM.  Thanks!
Title: Re: Traffic Simulator Z Development
Post by: z on May 31, 2009, 01:12:52 AM
Some people have responded to my previous post indicating that they were interested in the testing, but didn't know how to use Ilive's Reader.  Not to worry!  If you can use Windows Explorer, you can use Ilive's Reader.  What needs to be done is simple enough that I'll give step-by-step instructions, so that even someone who has never used the Reader before can follow them with ease.
Title: Comments on some of the Simulator Z traffic speeds
Post by: shlarin on June 19, 2009, 11:50:57 PM
Subway speeds:

Currently, the simulator allots a speed of 150 km/hr for subways and light rail.  I do not know of any comparable services in the world that regularly runs at such high speeds..  I think most systems (like NYC) rarely go above 60 or 70 mph..  so a limit of about 100-120 km/hr would be more reasonable.

Road and Avenue speeds:

50 km/hr translates to about 30 mph which is a bit on the low side for an empty road (now it's reasonable or even a bit fast for a congested road but the simulator automatically reduces speeds during congestion.)

My suggestion - 60 km/hr for roads, 80 km/hr for avenues.

When I build a city on a large map with a decent mass transit system, the subway and monorail lines end up near capacity (at 60,000+ people/day) while the roads are nearly empty (this doesn't seem to matter even in a city with a R $$$ majority - they'll still take the subway and bus while avoiding driving like the plague.)  I think closing this gap between the road and subway speeds might allow more realistic mass transit preference among sims..  just a suggestion.
Title: Re: Traffic Simulator Z Development
Post by: z on June 20, 2009, 12:04:21 AM
Due to the way the Maxis simulator works, making the vehicle speeds completely realistic would have a negative effect on traffic distribution, for reasons that are a bit too complex to go into here.

As for your city, when you say "decent mass transit system," how many subway lines do you have?  If your city is saturated with them, then yes, you'll get a lot of usage there.  Even in a real city, subways are faster than cars in rush hour.  Also, the 60,000 capacity you mention makes it sound like you're using the Ultra version of the simulator.  If you move down to the High version, you'll start to get some real congestion in your subways, and Sims should start moving more to their cars.
Title: Re: Traffic Simulator Z Development
Post by: Eagle on August 07, 2009, 08:01:25 PM
I am using traffic sim z medium & have a few questions.
1. What is the current version of traffic sim z?  I am not running the NAM, so I downloaded the z sim from a link on this thread.  It is ver v1_1a.
2. The values for the intersection effect in the DAT file are 1.0, 0.2, 0.4.  What exactly do these values represent?  I have read the thread & have a general understanding of intersection effect, but want to understand the math.
3.  The population background traffic values in the DAT file are 0.05, 0.2, 0.2.  Are these values related to the automata traffic generated or do they actually affect the traffic numbers used for traffic noise, etc?
4. What roadside bus stops & subway stations are preferred?  I am not running RTMT.  I tried using Deadwood's stops, & they worked fine except for capacity.  However, when I bumped up the capacity, they no longer show trips or calculate utilization in the query pop up. . . & I don't know how to correct this.
Title: Re: Traffic Simulator Z Development
Post by: z on August 08, 2009, 01:05:56 AM
Welcome to SC4D!  As the questions you have asked are actually support questions, I have answered them in the NAM Traffic Simulator Z and Data View Help (http://sc4devotion.com/forums/index.php?topic=6812.msg265199#msg265199) thread.
Title: Release of Traffic Simulator Z v1.2 - Beta 1
Post by: z on August 12, 2009, 12:18:59 AM
In the original Maxis traffic simulator, pathfinding was often poor at best - I remember Sims deserting their residences due to lack of jobs even though there were suitable jobs available literally right across the street.  Later traffic simulators improved this situation greatly, but the no-job zots were merely reduced, not eliminated, and it was generally a good strategy to put in as much mass transit in a city as you could afford, and hope that the Sims would find their way to at least a good portion of it.

Simulator Z has improved pathfinding to the point where no-job zots are a rarity in properly built cities, and the Sims can generally be counted on to take the fastest route to work.  The Maxis simulator gave the Sims all of three minutes to get to their jobs; if they couldn't find a suitable job in that amount of time, they were fired, and forced to leave town, resulting in a no-job zot.  Later traffic simulators extended this commute time limit, but it wasn't until Simulator Z that it was extended far enough so that the Sims could take a real-world amount of time to get to their jobs.

Making these improvements had an unanticipated side effect, though.  Since the rails (subway, el rail, commuter rail, and monorail and its variants) were always faster than roads, even highways, the increased pathfinding efficiency of Simulator Z means that the Sims now travel by various forms of rail whenever they can.  The result, as many people have noticed, is that there is much less road traffic in a city running Simulator Z than in a real city, as long as the SC4 city has a fair amount of rail networks.

Right now, there are two ways to remedy this.  Experienced SC4 players often overbuild rail networks, especially subways, as in the past that has been necessary for optimum traffic flow.  With previous versions of Simulator Z, I have increased the monthly cost of subways to discourage this practice, until this cost currently stands at six times the original Maxis cost.  But it is still not hard to have a thriving, profitable city with lots of subways and other rails, and with the roads barely used.

One way to restore balance is to reduce the amount of rail networks in a city, forcing the Sims back onto the roads.  If a realistic amount of rail networks is used, then this will happen.  Another way to restore balance is to use the Low version of Simulator Z, thereby limiting the use of rail networks, and again, forcing more Sims onto the roads.

The only problem with these methods is that they are rather artificial.  Ideally, the traffic simulator should produce a reasonable balance of traffic distribution, as long as you have provided sufficient traffic capacity for your city.  The traffic simulator even has properties that allow the Sims' preference for travel types to be weighted toward cars or mass transit, and these properties can be set for each wealth level.  From its initial release, Simulator Z increased the Sims' preference for cars, and at first, this had a real effect.  But as the efficiency of Simulator Z's pathfinder increased in subsequent releases, it overwhelmed these preferences.  So I have spent a while looking at the dynamics of this situation, doing a lot of testing and seeing where the problem lay, and in the end I have come up with what appears to be a better version of Simulator Z.

Hints of what the source of the problem is can be seen in the problem's description above.  In earlier traffic simulators, rails had to be significantly faster than roads to attract Sims to them.  That is no longer the case.  Simulator Z started with the same speeds for rails as the old CAM simulator, which is what I used as my starting point for Simulator Z.  These speeds were either greater or equal to those of the original Maxis speeds.  Through my experiments, I have found that reducing them significantly helps balance traffic automatically.  And it does so without causing any performance degradation; in fact, cities appear even more robust using Simulator Z with the lower rail speeds.  I believe that this is due to the fact that the game intrinsically likes to see traffic on the roads, and increasing this traffic has various positive effects.

What is a "significant" reduction?  For all rails except monorail and its variants, it's 30%.  This makes most rails slower than highways for the first time.  Monorails were a tricky question; in the real world, they aren't significantly faster than el rail or subway.  (For example, an official of the Seattle monorail recently stated that the monorail's average speed, including stops, was 27 mph (43 kph).  This was in response to a charge that its average speed was only around 20 mph (32 kph).)  However, monorails also serve as the basis of High Speed Rail, and according to Wikipedia, the minimum cruising speed of high speed rail is 200 kph.  What to do?

First of all, in general all the speeds in Simulator Z are based on cruising speed, and do not include stops.  Furthermore, in this new release of Simulator Z, all vehicle speeds are actually around the upper limit of their real-world cruising speed.  But this still leaves a huge gap between real-world monorail speed and the minimum speed of high speed rail.  It's clear that Maxis intended that the monorail be a high speed form of transit, and countless cities are built with that assumption in mind.  So what I did was to use the minimum cruising speed of high speed rail, or 200 kph.  This represents a 20% reduction from the current monorail speed, as opposed to the 30% reduction for other rails.  And coincidentally, it just happens to be the original monorail speed used by Maxis.

In general, reducing the speeds of the rails reduced their usage slightly.  But monorail usage actually went up significantly!  Part of this is undoubtedly due to the fact that monorail speeds were not reduced as much as other rail speeds, but part was also undoubtedly due to the fact that there are fixed time costs in transit that did not change, and a fast monorail becomes even more attractive under those circumstances.

Finally, there's the Bullet Train Mod (BTM).  Technically, a bullet train is just another name for high speed rail, and runs at the same speed.  But in SC4, it has been used to designate an extra-fast form of high speed rail.  I decreased the speed of the BTM by 25% to 300 kph, which happens to be the original speed of the BTM in SC4.  Like the monorail, I would expect to see its usage increase in the new Simulator Z.

Bus speeds were unchanged; as a result, bus usage tends to increase a bit over time along with car usage.

To summarize, here are the speeds (in kph) of the rails in the original Maxis simulator, the current Simulator Z, and the new Simulator Z:

[tabular type=2]
[row] [head]Simulator[/head] [head]Subway[/head] [head]El Train[/head] [head]Freight Train[/head] [head]Commuter Rail[/head] [head]Monorail[/head] [head]Bullet Train[/head] [/row]
[row] [data]Maxis[/data] [data]150[/data] [data]150[/data] [data]150[/data] [data]150[/data] [data]200[/data] [data]200[/data] [/row]
[row] [data]Simulator Z v1.1.1[/data] [data]150[/data] [data]150[/data] [data]150[/data] [data]200[/data] [data]250[/data] [data]400[/data] [/row]
[row] [data]Simulator Z v1.2[/data] [data]105[/data] [data]105[/data] [data]105[/data] [data]140[/data] [data]200[/data] [data]300[/data] [/row]
[/tabular]

I have done extensive testing of these new speeds on my cities using the different capacities of Simulator Z, and I find it to be a distinct improvement, though in general, the difference was subtle, and in no case was it drastic.  But it was always positive.  As might be expected, the biggest difference was in highway usage.  Furthermore, changes were gradual; it typically took about ten years for real changes to be seen.  At the ten year point, change in traffic patterns was continuing in a positive way, but this was as far as I took my tests.

I would like to encourage as many people as possible to try out the new version of Simulator Z, as I think it is a real improvement over the current version.  It's recommended to run it at least ten years (and possibly longer) before evaluating it; the Traffic Volume Graph is one of the most useful tools for seeing what's going on here.  It would be very helpful for some people to run their cities with this simulator for 20 years or longer to see what happens.  Please post your experiences with this simulator in this thread, along with any other comments you may have.  If no problems are found with this version of the simulator, it should be released as the standard Simulator Z in the next NAM release.

To use the new version of Simulator Z, download the attached zip file, which contains all capacities and types of the simulator.  It is important to already have the current version of Simulator Z installed via the NAM installer, as this way it will be in sync with the other files that get installed along with it.  Then replace the version of Simulator Z in your Network Addon Mod folder with the identically named file from the attached zip archive.  If you are using the BTM, you should pick the file that has the same name but also has "BTM" in it.  Good luck!
Title: Re: Traffic Simulator Z Development
Post by: pierreh on August 12, 2009, 02:02:02 PM
I have installed the V1.2 Beta version of the Simulator, High setting, no BTM and no Park-and-Ride, and I am eager to see the effects.

A question: for the tests do you prefer 20 years of running on a 'static' city, i.e. no further zoning, roadway layout, etc, or can one keep developing the city during those 20 years? (It means quite a bit of play time, and in my case it will mean running in multiple successive sessions: is that a problem?)
Title: Re: Traffic Simulator Z Development
Post by: z on August 12, 2009, 03:06:35 PM
The ideal test would be on a static city.  But as you point out, that is quite a bit of play time.  A lot can be learned through normal play, especially if the city is already large.  My tests were all on static cities, so if people want to run this simulator in dynamic cities, I think a lot of useful data can still be obtained.  The main thing is to verify that the new settings don't make anything worse.

One thing that I noticed is that the proportion of high-wealth Sims tends to steadily increase under this simulator.  I'd be very interested to know if other people see this effect, or if it's just due to the type of cities I'm running.  The easiest way to see this is to look at the Jobs & Pop graph.
Title: Release of Traffic Simulator Z v1.2 - Beta 2
Post by: z on August 15, 2009, 08:42:09 PM
I've tested the new version in all build-up city tiles for at least 10 ingame years (longer only if expansion was planned) and so far the difference is barely noticeable. If both EL/GLR and heavy rail are running parallel for some length - in some cases I "retrofitted" parts of rapid transit into former four-track corridors in older cities -, EL/GLR usage ceased at all compared to v1.1.1. In general the number of rail road commuters, who switched to cars or buses, went down by max. 10%, but after reading your explanation I really expected a more significant change. Maybe it is due to my rather small cities (103.000 in the biggest one, most are well under 50.000), relatively close proximity of workplaces; a habit that still remains from playing with the old Maxis simulator; and only a small number of railway lines? On the other hand I encountered no problems or strange game behavior.

Yes, your experience is what I would expect, especially considering the city configuration you described.  The biggest difference will be seen in large, spread-out cities, and even then, as I mentioned earlier, it won't be a drastic difference.

Some of you may recall that a few months ago, I made a request in this thread for volunteers to test a new version of Simulator Z.  People volunteered and did the tests, and my thanks to all of them for their work.  At the time, the tests showed no significant difference from the standard Simulator Z.

In my post announcing the Beta 1 version of Simulator Z v1.2, I mentioned that the simulator's efficiency combined with the large differences in vehicle speed overwhelmed overwhelmed some of the preferences expressed in some of the simulator's other parameters.  But with the speed ranges reduced in Beta 1, I decided to revisit the other change I had been considering.  Sure enough, it now had an undeniable effect, although still small.  And the setting the had the best effect had been hinted at in the initial results a few months ago.  Combined with the speed reductions, there is slightly more road traffic, along with an even greater increase in monorail/HSR/BTM usage.  As a result, I am incorporating this change into what is now Beta 2 of Simulator Z v1.2.  Aside from this one addition, everything else is the same as in Beta 1, including the new travel type speeds.  I expect this to be the last beta for this version of Simulator Z, and I would appreciate it if people would test it out and let me know how it works for them.  Don't be surprised if the differences are small enough in some cities not to be noticeable.  Please see the end of the first thread on this page (the part after the chart) for how to install and test the beta version.  All feedback is appreciated.  Thanks!
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 16, 2009, 12:07:25 AM
Hey z, it's me again.

The traffic situation in my region is pretty much the same (overloaded roadways, high bus use in certain corridors, no rapid transit, yet).  I've tested beta 2 on a few city tiles in my region. 

My Downtown is "stable", no development occurs when I unpause.  Traffic from other city tiles sometime fluctuates, but then revert back to previous levels.  During the 10 years, population percentages/numbers stayed the same.  Automobile use is up slightly, pedestrian and bus use dropped slightly.  Traffic congestion stayed about the same, though in certain areas, distribution among streets changed.  Looking at the volume views, pedestrian volumes were a bit less.  But previously, some roadways had buses at red and orange levels, and now nothing's over yellow.  Auto and overall roadway volumes look similar.  The one big difference was that commute time dropped from 65 minutes to 20.

Though, in another stable city tile, all the trends are the same, but commute time only dropped a few minutes.  Other city tiles were inconclusive because of either neighboring tiles completely changing commute patterns or they were really static, and car-only.

z, I've been wondering.  I know we can't get real region-wide pathfinding.  I've been thinking of ways to get around the limitations and force traffic to city tiles with available jobs.  Is there a way to adjust the penalty to commute to another city tile?  I've basically avoided unpausing, then resaving certain ones because they route intercity traffic to undesired places.  It's one thing I want to experiment with.  Though, I can see a problem there, because it would undoubtedly kill multi-tile commuting.  Another alternative could be modifying toll booths and putting on certain neighbor connections.  Because of the linear nature of my region, limited roadways and heavy directional traffic from the suburbs, the toll booths would discourage commuters from going the wrong city tile (just because it has a couple of commercial jobs) and possibly get them going the desired way (to town and jobs).
Title: Re: Traffic Simulator Z Development
Post by: z on August 16, 2009, 12:50:46 AM
What you describe in general makes sense to me for cities with your layout and no rapid transit.  However, I haven't seen the cities (at least not recently), and I don't know what capacity version of Simulator Z you're using.

Don't pay too much attention to the commute time graph.  I've fixed it as much as I could, but due to a game bug, it's never going to show you the proper times.  And with Simulator Z, commute time is nowhere near as important as it is with other traffic simulators.

As for forcing traffic to city tiles with available jobs, the game is supposed to do that automatically.  The main cases in which this doesn't work are when people are using CAM, and the CAM demand bug skews everything.  I certainly wouldn't recommend giving up CAM, but we may need to wait for a fix for this bug before this feature works properly.

There is no way to adjust the cost of commuting to another city tile.  And the only real effect toll booths have (aside from the income) is a congestion effect; only to that extent do they affect traffic flow.

In the relatively near future, I'll be polishing up my ESURE package.  This package includes express subways, which are extremely helpful for intercity commuting.  Once I've got ESURE working the way I want, I'll post it on the LEX, and that will help you out at least to some extent.  The fix for the CAM demand bug should also make a big difference, though I have no idea when that will be ready.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 16, 2009, 03:16:44 AM
Thanks for clearing all of that for me.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on August 16, 2009, 05:03:56 AM
Here are the results of 20 years of running the latest version of Simulator Z, V 1.2 Beta 2 freshly dowloaded, High setting.

City data: This is a mature city occupying most of its tile; it is an early development with lots of things that I would no longer do, or do quite differently. The subway was installed later on the mature city, replacing the busiest bus flows, but it still left out some areas of the city. Railroad lines are relatevely underdeveloped. The city has connections to two other smaller cities, one east, the other west of it.

Population: 527'699 at start of test, 544.752 at end of test (20 years + 3 months later). The population rose towards 540.000 in the first 5 years, then remained stable and started again to grow slowly in the last 5-6 years.

Aside from fixing schools (budget and adding the city university when the game university overflowed) and health (adding hospitals and clinics) and deleting two or three abandoned buildings I did not interfere with the city during the test. All pictures below were taken at the end of test.

City zoning, showing the global layout:

(http://img7.hostingpics.net/pics/167176Sparta_zones.jpg) (http://www.hostingpics.net/viewer.php?id=167176Sparta_zones.jpg)

Road traffic flow, showing that there is very little congestion

(http://img7.hostingpics.net/pics/702039Sparta_traffic_flow.jpg) (http://www.hostingpics.net/viewer.php?id=702039Sparta_traffic_flow.jpg)

Road traffic global volume:

(http://img7.hostingpics.net/pics/511372Sparta_traffic_volume.jpg) (http://www.hostingpics.net/viewer.php?id=511372Sparta_traffic_volume.jpg)

Bus traffic:

(http://img7.hostingpics.net/pics/18441Sparta_traffic_bus.jpg) (http://www.hostingpics.net/viewer.php?id=18441Sparta_traffic_bus.jpg)

Subway traffic, showing also the subway network; only one 'line' is well used, the others much less:

(http://img7.hostingpics.net/pics/769006Sparta_traffic_subway.jpg) (http://www.hostingpics.net/viewer.php?id=769006Sparta_traffic_subway.jpg)

Train traffic:

(http://img7.hostingpics.net/pics/763250Sparta_traffic_trains.jpg) (http://www.hostingpics.net/viewer.php?id=763250Sparta_traffic_trains.jpg)

Jobs and population:

(http://img7.hostingpics.net/pics/507029Sparta_jobs_and_pop.jpg) (http://www.hostingpics.net/viewer.php?id=507029Sparta_jobs_and_pop.jpg)

Travel time:

(http://img7.hostingpics.net/pics/940221Sparta_travel_time.jpg) (http://www.hostingpics.net/viewer.php?id=940221Sparta_travel_time.jpg)

And finally the graph that is surely the most interesting, that of the Traffic density. The previously Simulator setting was Z High (V1.1 if I recall correctly). The effect of the new version of the Simulator is quite clearly visible.

(http://img7.hostingpics.net/pics/548002Sparta_traffic_density.jpg) (http://www.hostingpics.net/viewer.php?id=548002Sparta_traffic_density.jpg)

I'll be interested in the interpretation of these results. I have a couple of other cities on which I could perform a similar test some time next week.
Title: Re: Traffic Simulator Z Development
Post by: Eagle on August 16, 2009, 01:16:18 PM
OK, I tested v1.2 beta.  Before the test, the city was running on v1.1a high with one modification: bus speed was bumped up to 5 kph below car speed.  The city has a good bus & passenger rail network.  It ran for ten years & here are the numbers:
Before--->After. Population(655k--->638k). Cars(230k--->235k). Bus (175k--->150k).
Passenger rail(210k--->200k). 
I think the large drop in bus traffic was due partly to the speed difference as noted above.  No ill effects noticed with running v1.2 beta.
Title: Re: Traffic Simulator Z Development
Post by: z on August 16, 2009, 04:46:15 PM
Here are the results of 20 years of running the latest version of Simulator Z, V 1.2 Beta 2 freshly dowloaded, High setting...

Everything looks good here, except that that last graph (which is the only one containing historical data) makes no sense at all, for at least a dozen different reasons.  The most likely explanation I can think of is that the city was not previously running Simulator Z V1.1 High, as you thought.  Could you please try rerunning it with that Simulator (or v1.1.1, which is identical for these purposes) and see what you get?  The version in the current NAM would work fine for this test.

@Eagle:  Those results look good.  The reduction in the bus traffic is only about 15%, which isn't too much, especially considering that the previous result was with your mod.  And bus ridership is still about 64% of car traffic, which seems quite reasonable.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on August 17, 2009, 01:24:56 PM
I installed the version of Simulator Z High dated from 16 January 2009, that came with the March 2009 release of NAM. And I reran the 20 years test on the same city. The results for Travel Time and Traffic Density are not very much different from the previous test:

(http://img5.hostingpics.net/pics/214489Sparta_travel_time_1.jpg) (http://www.hostingpics.net/viewer.php?id=214489Sparta_travel_time_1.jpg)

(http://img5.hostingpics.net/pics/800177Sparta_traffic_density_1.jpg) (http://www.hostingpics.net/viewer.php?id=800177Sparta_traffic_density_1.jpg)

I cannot think of a dozen different reason why the graphs make no sense at all, I can only think of one: game speed. I normally play at low speed, because I like to see things developing at a pace I can control, and adjust/correct if it does not go the way I would like to have it. For the 20 years tests I played at high speed. Could it be that, depending on the game speed, some computations that take a lot of juice (and if I recall correctly, paths computations in the Simulator are among the most processor-intensive tasks in the game) are not performed at the same pace relatively to the game's calendar, or are performed differently, or even not at all in some cases? Pure conjecture on my part of course - although not entirely, because when running a previous simulator test (involving a monorail parameter) I had noticed differences in stations occupation and traffic figures for the same period of city time, depending on the speed of the test.

I intend to rerun the first five years of the test, using the 1.2 beta version of the Simulator, at low speed, and produce 10 year graphs which will show the last 5 years before the test and the first 5 years of the test. I can try to fit this in my schedule for tomorrow. During the last 5 years prior to the test at least, the city was running with Simulator Z high, most likely the above mentioned version.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on August 18, 2009, 04:11:34 AM
I performed the 5-year test at slow speed, with Beta 2 of version 1.2. I find the results interesting. Here are the two 10-year graphs:

(http://img5.hostingpics.net/pics/868392Sparta_travel_time_slow.jpg) (http://www.hostingpics.net/viewer.php?id=868392Sparta_travel_time_slow.jpg)
(http://img5.hostingpics.net/pics/727402Sparta_traffic_density_slow.jpg) (http://www.hostingpics.net/viewer.php?id=727402Sparta_traffic_density_slow.jpg)

Since the test was performed for exactly 5 years, the beginning of the test, T0, is right at the middle of the graphs. This shows that the 'singularity', when travel time increased substantially and traffic densities changes also markedly, happened before the beginning of the test - about 3 years before. What caused that singularity, I have no recollection, having played in recent times with several cities concurrently, for development as well as for various tests.

The fact that the singularity happened before the testing period was less visible on the 50-year graphs for the 20-year tests. T0 on these graphs is at 3/5ths of the horizontal scale; however, without measuring exactly, one can see that the singularity occurs before 3/5ths of the graph are reached.

Contrary to what I assumed, game speed does not appear to have much effect, if at all. The 5-year graphs show by and large the same variations as the 50-year graphs during the 5 years following T0.

Does the 50-year traffic density graph now make more sense?
Title: Re: Traffic Simulator Z Development
Post by: z on August 18, 2009, 05:18:04 AM
Yes, all your results now make sense.  The version of Simulator Z in the January NAM is 1.0, and for most cities, there will not be a significant difference between v1.0 and the current v1.2 beta.  This is the main reason I'm not calling it v2; it's essentially just a better tuned release.  If you look at the traffic volume graphs for the January NAM version of Simulator Z and the ones using v1.2, you see that they are quite similar - there is hardly any difference at all.  This does make sense.  It's the part before what you term the singularity that didn't make sense, as you originally thought that that was an earlier version of Simulator Z.  But it couldn't have been - your later experiments used the earliest released version of Simulator Z, and it behaved much like the current version.  So either the part before the singularity was an early alpha version of Simulator Z, or, more likely, it was a different simulator altogether.  The pattern of traffic usage before the singularity does not look like that of any version of Simulator Z, but it does look a lot like that of many of the other simulators.

Does this make sense to you?
Title: Re: Traffic Simulator Z Development
Post by: pierreh on August 19, 2009, 04:10:23 AM
Absolutely!

I did not keep a journal of what I did to the city in previous game years, so I would of course never swear that it had been run with Simulator Z for a long time, and evidence shows that it did not, until about 3 years before the start of the test: strange but conceivable. We will never know but that is irrelevant.

Do you need more testing? I intend to apply V1.2 to the city with the monorail line, that was already used for an earlier test.
Title: Re: Traffic Simulator Z Development
Post by: z on August 19, 2009, 04:50:16 AM
No, I don't think any more testing is needed.  Thanks for your help!
Title: Release of Traffic Simulator Z v1.2 - Beta 3
Post by: z on August 21, 2009, 02:08:14 AM
The Beta 3 release of Simulator Z v1.2 is now available.  Like each of the previous two betas, it optimizes a different part of the simulator.  Beta 3 specifically adjusts a parameter that directly affects commercial and residential demand; the result should be a slightly better balance.  The biggest change was made to the Ultra version of Simulator Z; successively smaller changes were made to the High and Medium versions; and no change was made to the Low version.  Although the parameter changed specifically affects demand, simulator parameters often have unexpected effects on seemingly unrelated aspects of the game.  I always test these versions thoroughly before releasing them even for beta test, but my range of cities is obviously limited.  Please let me know what effects you observe from this change; I am particular interested in hearing from users of the Ultra version of the simulator, where the effects should be most noticeable.  I have noticed what seems to be a slight increase in car usage, but it's hard to tell if this is statistically significant; I'd be interested in hearing if other people noticed the same thing.  In any case, I'd be interested in hearing about any changes you observe.  Thanks!
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 21, 2009, 04:58:26 AM
I have pictures this time!  I tested in 3 side-by-side city tiles (called in-town Capitalis) with Ultra for at least 10 years each.  I did not save after each test.  Basically, all the trends were the same as w/ beta 2: flat population/jobs, slight increase in car usage, slight drop in ped/buses.

Here's the zoning layout:
(http://img20.imageshack.us/img20/708/zoning.jpg)

There is a single east-west freeway that cuts through the middle of the city tiles.  Basically, my preferred commute patterns are for the west, north and east suburban commuters to converge in town.  What ends up happening is that commuters from the valleys to the north automatically go to the closest neighbor connection.  Most commuters from the eastern suburbs go westbound on the freeway, stay on it, and go to the next city tile.  Vacant jobs are plentiful along the southern shore.  Commuters go past the left edge of the map and then they are in the western suburbs.  As for western suburban commuters, many do go eastbound, but many others go westbound as well.  To the west of the picture there are a lot of industrial jobs on the south edge of the map (ignored by the commuters).  But there is a big potential for an eternal commuter loop, and that is the reason why I've been wanting commuters to go toward town to find jobs.

Anyways, here are before and after graphs:

Congestion:
(http://img269.imageshack.us/img269/8836/basecongestion.jpg)

(http://img215.imageshack.us/img215/4039/updcongestionq.jpg)

Road Volume:
(http://img198.imageshack.us/img198/4032/baseroad.jpg)

(http://img198.imageshack.us/img198/7145/updroad.jpg)

[Removed other graphs]

And also, what exactly is that commercial/resdential parameter?  I don't know if I experienced something out of the ordinary.
Title: Re: Traffic Simulator Z Development
Post by: z on August 21, 2009, 05:12:21 AM
This all looks reasonable to me.  Your before and after pictures are very close, and as there is some randomness even in running the same simulator from the same starting point, I see nothing to be concerned about here.

The one thing that surprises me is that your industrial jobs are unfilled - they're close enough to residences that Sims should be using them.  The most likely explanation is lack of industrial demand.  Could you post a picture of your RCI Demand Graph?

As for the parameter, it's the Customers/Traffic Noise Coefficient.  And aside from the lack of industrial workers (which is not affected by this parameter), you do not appear to be experiencing anything out of the ordinary.

Thanks for testing the new beta!
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 21, 2009, 05:58:29 AM
Oh, that parameter.

All three city tiles are victims of the aftermath of removing the Residential Halver mod.  Census repository shows messed up stats in all three.  I've actually tried the CAM/Simcity_1.dat patch thing, it does fix the workforce and residential capacity, but commute patterns are virtually the same.

Left city tile:
(http://img190.imageshack.us/img190/9163/sector21.jpg)
Taxes:  R$, CS$, CS$$, I-Ag, I-D, I-M @ 9.0%, the rest at 15/20% to discourage them

Middle city tile:
(http://img19.imageshack.us/img19/17/sector22.jpg)
Taxes:  Generally <=9.0%, but CS$$$ at 9.9%

Right city tile:
(http://img40.imageshack.us/img40/9049/sector23.jpg)
Taxes:  All 9.0%

The industrial along the shore include all the three types.  There might be an over-supply of manufacturing, but all three industries have many vacant jobs.  Commuters not taking industrial jobs is something I've always experienced throughout playing SC4.
Title: Re: Traffic Simulator Z Development
Post by: z on August 21, 2009, 02:02:24 PM
I think that first graph tells the whole story.  But your tax policies have created that situation.  So I don't think there's anything to blame beyond the tax policies here, unless you change them and still have a problem.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 21, 2009, 06:27:42 PM
I didn't know tax policies affected commute patterns...?  There definitely is an oversupply of manufacturing in the region, according to the Census Repository in several city tiles.

In the left city tile, I discouraged R$$ and R$$$ because it's suppose to be a R$ neighborhood.  I discouraged all commercial except CS$ and CS$$ to push demand to the middle and right city tiles.  I've corrected my previous post, I-M taxes are at 9.0% on the left city tile.  I lowered all industry taxes to 8.0%, and ran for 10 years.  There were only a few I-HT built.  There were still tens of thousands of commuters staying on the freeway and ignoring jobs at the south edge of the city tile.

The eastern suburbs are all R$$.  The right city tile doesn't have enough jobs.  So they go into the middle, then left city tile, but both those tiles have almost 700,000 eternal commuters each.   :'(  Maybe that's why they're all skipping cities.  Yes, jobs close enough to homes are certainly taken, but jobs in the southern 1/4 of the city tiles are more likely to be vacant.  It really does seem that the "closest job" is always in the next city.

Here's a large picture of the region: http://img269.imageshack.us/img269/2712/bluecapitalis.jpg (http://img269.imageshack.us/img269/2712/bluecapitalis.jpg)  I think you can infer what my preferred commute patterns are versus what the game wants.

I'm going to try re-run the traffic simulations in all the city tiles and save this time.
Title: Re: Traffic Simulator Z Development
Post by: z on August 22, 2009, 12:25:10 AM
I didn't know tax policies affected commute patterns...?

Definitely!  Taxes influence demand, which in turn influences the number of jobs actually available.  And Sims go where the jobs are.

Quote
There were only a few I-HT built.

High tech industry requires many things that are interdependent on each other.  That's a complex topic beyond the scope of this thread, though, as it really has little or nothing to do with the traffic simulator.  But your high taxes on middle and high wealth Sims are definitely discouraging high tech jobs.

Quote
  There were still tens of thousands of commuters staying on the freeway and ignoring jobs at the south edge of the city tile.

The eastern suburbs are all R$$.  The right city tile doesn't have enough jobs.  So they go into the middle, then left city tile, but both those tiles have almost 700,000 eternal commuters each.   :'( 

I'm not clear here.  Are there more than those three cities in what you're referring to as an eternal commuter loop?  Because in an eternal commuter loop, Sims are constantly going from one border to a different one, and you can't do that with just three cities line up in a row.  I looked at the picture you linked to, but I couldn't gather any more information from that.

On the other hand, if there are other cities involved and you really do have an eternal commuter loop with 700,000 Sims, that's going to mess up your entire economy.  You'll need to break the loop at at least one border to get things working well.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 22, 2009, 02:59:19 AM
Whoops, a major mistake in my wording.  I meant there are 700,000 SimNation commuters each in those two city tiles.

As for the eternal commuter loop, if you look at my region, there's the airport (look for the off shore runway).  To the north, that area is made up of several city tiles, all connected in a way that has the potential for an eternal loop.  I don't believe there are other loops in the region.

Also, for "There were only a few I-HT built", there were thousands of dirty, manufacturing and high tech already in the city tile.  I meant that only a couple of new I-HT buildings that were built after lowering taxes.

Taxes >>> demand >>> jobs >>> ... >>> where Sims commute to... quite a stretch.
Title: Re: Traffic Simulator Z Development
Post by: z on August 22, 2009, 04:37:41 AM
Taxes >>> demand >>> jobs >>> ... >>> where Sims commute to... quite a stretch.

Actually, that's one of the simpler relationships in this game.  Things can get very complex in SC4 very quickly.

Anyway, at this point the traffic simulator appears to be working fine in your cities.  Do you see any problem areas with it that I don't?
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 22, 2009, 10:46:24 PM
That particular relationship, I understand parts of it, but I did not previously consider it as a whole.

As for my issues, I think I've already addressed them all (somewhere) in this thread.  The reoccuring and unsolved ones are all bumping against game limitations, so there's not much that can be done for certain problems.

So, yes, the traffic simulator is doing a good job, with all that can be reasonably asked for.  Thanks for all your help.
Title: Re: Traffic Simulator Z Development
Post by: z on August 25, 2009, 03:00:17 AM
People have probably noticed that my changes to Simulator Z at this point fall into the area of fine tuning - I don't think there's a lot more to be done to improve the basic simulator.  However, there's a whole area of customization that can be opened up, allowing people to tune the simulator to their personal preferences using a special configuration tool (most likely, GoaSkin's NAM Tool).  It became clear from a discussion in the NAM Traffic Simulator Poll (http://sc4devotion.com/forums/index.php?topic=8611.0) that a lot of people would be interested in this type of customization, so I am now tentatively planning to implement it.  Such customization would include the following:


Comments are welcome, as always.
Title: Re: Traffic Simulator Z Development
Post by: RickD on August 25, 2009, 03:13:23 AM
I like this idea. Especially increasing the cost. Over the years I became bored with the management aspect of the game. It is way too easy. I never need to worry about money. Raising the network cost could make this interesting again.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 25, 2009, 03:47:00 AM
[Moved to this thread]

I want that control!  I'm curious to know how bus lanes would work.  Would they be available to other roadway networks as well?
Title: Re: Traffic Simulator Z Development
Post by: z on August 25, 2009, 04:40:19 AM
Highway bus lanes lanes would be implemented just by increasing the speed of buses on highways.  If you wanted the equivalent of bus lanes for all your road types, you would just use the Bus Usage Multiplier.
Title: Re: Traffic Simulator Z Development
Post by: z on August 27, 2009, 12:02:55 AM
It occurred to me that if I give the player the option of adjusting travel type fares, we might want to tie that to residential demand.  For example, if you triple your bus fares, Sims might be a little less interested in living in your city.  So this would add yet another dimension to managing transit.  What do people think of that idea?
Title: Re: Traffic Simulator Z Development
Post by: emgmod on August 27, 2009, 12:42:39 AM
I always wanted to modify fares. I like the idea.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on August 27, 2009, 03:57:11 AM
I don't think the mass transit fares would affect residential demand (unless there is that kind of relationship I'm not aware of).  I think it should be tied in with the wealth car-transit chance use.  Higher fares will discourage passengers, while lower fares will increase ridership.  R$$$ would be less affected:  they're not likely to ride transit, but can afford higher fares.  Low fares would help R$, and they can only pay so much for a ride.  R$$ are swayed by low prices, but are turned off by high fares.  I guess maybe 1% change for R$$$, 5% for R$$ and 10% for R$, for a $1 change in fares, or something like that.

And, for the bus lanes, I was hoping for real dedicated lanes, for limited uses in my region.  But, that's just for my situation.  Having bus speed different from car speeds should be an available choice.
Title: Re: Traffic Simulator Z Development
Post by: z on August 27, 2009, 04:29:37 AM
I don't think the mass transit fares would affect residential demand (unless there is that kind of relationship I'm not aware of).  I think it should be tied in with the wealth car-transit chance use.  Higher fares will discourage passengers, while lower fares will increase ridership.  R$$$ would be less affected:  they're not likely to ride transit, but can afford higher fares.  Low fares would help R$, and they can only pay so much for a ride.  R$$ are swayed by low prices, but are turned off by high fares.  I guess maybe 1% change for R$$$, 5% for R$$ and 10% for R$, for a $1 change in fares, or something like that.

That's a very good point, although that's a much more complicated relationship.  It seems to me you'd have a combination of the two processes; lower wealth Sims might be forced out of town by higher fares, but middle wealth would simply change transit types.  And high wealth wouldn't care.

I'll have to think about this some more, and figure out if I have the knowledge to model this properly.  Otherwise, I'll just leave in the ability to adjust fares, but without side effects.  Other ideas are welcome, too.

Quote
And, for the bus lanes, I was hoping for real dedicated lanes, for limited uses in my region.  But, that's just for my situation.  Having bus speed different from car speeds should be an available choice.

Having the automata obey bus lanes is just not possible in the current game.  But at least it's possible to create the effect on commuting.

BTW, bus speeds are currently different from car speeds - they're slightly lower (except on highways), to account for all the stops that buses make.  But you'll be able to change this.
Title: Re: Traffic Simulator Z Development
Post by: k808j on August 27, 2009, 07:18:57 AM
@z

Would sim z medium cause the sims not to use the buses or bus use not show in traffic data view?
Title: Re: Traffic Simulator Z Development
Post by: z on August 28, 2009, 01:32:52 AM
No version of Simulator Z should do that.  If you're actually having that problem with a current version of Simulator Z, could you please provide the details in the NAM Traffic Simulator Z and Data View Help (http://sc4devotion.com/forums/index.php?topic=6812.0) thread?
Title: Re: Traffic Simulator Z Development
Post by: HappyDays on October 12, 2009, 02:03:32 PM
Dear Z,

I've been using Simulator Z since it first violently emerged onto the scene, and I absolutely loved it. However, its sheer efficiency and the fact Sims are really bloody stupid resulted in the complete slaughter of road usage in favor of my vast, extensive subway systems. In turn, this resulted in my commercial sectors being brutally harmed because no one actually used the roads anymore.

I just today popped in your 1.3 beta specifically because you mentioned changes to the Ultra part of the simulator (The only one I use). Suddenly, I have road usage! Business that have had low customers forever now have high customers! Highways that I built just because I feel every large city needs a highway system are actually used! Life is happy for everyone! Hamsters and rangers everywhere, rejoice!
Title: Re: Traffic Simulator Z Development
Post by: z on October 13, 2009, 04:51:33 AM
I am very glad that this worked for you, HappyDays!  I have been discovering that the changes made in the three betas that comprise V1.2 are actually a lot more powerful than I anticipated, and have solved the traffic problems of a lot of people.  For this reason, I am now recommending that all Simulator Z users download and use the Beta 3 version of Simulator Z V1.2, which I now consider to be of release quality, and which I am now planning to release as the final V1.2.  So that people don't have to go back through this thread searching for this version, it can be obtained by clicking on this link (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=6122).
Title: Re: Traffic Simulator Z Development
Post by: redraider147 on October 14, 2009, 09:11:45 PM
Z,

As you know I am always in favor of making the game more realistic, especially from the transit front. I personally have always wanted adjustable fares/tolls. I have never been able to get a mass transit system to pay for itself, due to the fare limitation where if i could raise the fares even 1 sim., it would put me over the top in most cities. the fares combined with E-SURE would make for a much more realistic system...now if only we could set specific bus routes. (just kidding there...unless it somehow is found to be possible. :-P )

as for the HOV/carpool/bus lanes, it would have an immense impact on my suburbs where I have hundreds of thousands of sims a day commuting via the freeways and tollways. this would not extend to avenues though, right?

I would also love the ability to tweak other things myself, such as the network speeds or capacities.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 20, 2009, 12:25:08 PM
Z,

I've been using the Z-low pretty much since I started playing (about 2 months now). Although probably for the last month I've spent more time in the reader and testing than actually playing.
Read through most of the discussion from you, Mott, Jplumbey, etc. about how the traffic sim works. I've tinkered my Z so much I suspect it looks more like A or B just with better pathfinding.

I've got a couple unanswered questions both about Z and traffic sim in general:

1. I keep seeing the pathfinding heuristic mentioned but I cannot find it in ilives reader. I am assuming based on the values observed and in discussion threads that it is the "nearest destination attractiveness" but I just want to be sure.

2. If commute time is reset after leaving the tile then isn't 60 WAY overkill? The maximum trip length for a large tile is 1024 (256 up, 256 across x2). Even a maximum congested highway in Z would only need 31 time units to cross the tile and back.

3. Are commute time units independant from the timeclock for a sim day (and I am talking about the actual calendar day not the day/night day) ? I have not seen any mention of this anywhere. If they aren't I'm thinking that there are only 48 units in a sim day. I'm basing this off Maxis statement that "sims will only commute about 2.5 hours a day" and the default max commute of 6. Consider their "about 2.5 hrs" to actually mean 3 hrs and you get a 30 minute time unit (because I don't think that they arbitrarily picked 6). If this is the case then the max commute really should not be altered at all so speeds should be increased instead of time units?

4. Is capacity per time unit or for total day or half the day or what? Going by (I think it was) Motts figures, let's say I want 2400 cars per hour on road. Do I figure out my commute time into hours and then multiply the capacity by that? One-ways since they are theoreticly only used half the day do I set the capacity at what I want or double it or half of it? Something that seems very simple, cut and dried actually turns out to be quite complicated.

5. Doesn't making bus generate traffic defeat their purpose? If each sim that rides a bus still count as a vehicle then you aren't reducing the congestion any. I remember you saying you found a workaround but going through the file in the reader I could not find any variable that would seem to effect it.

6. Type does not generate traffic(or is it not affected by traffic? I'm sorry I am at work right now)==not affected by congestion? Or in other words: Are my pedestrians (and bus if I decouple from traffic) going to run around at 130% speed because there is never any congestion for them or are they completely unaffected by the congestion modifier?

7. If type doesn't generate traffic (i.e. peds again) should they not count against capacity (i.e. transit switches) and therefore station capacitys should never have to be inflated for the peds? (like RTMT for instance)

Title: Re: Traffic Simulator Z Development
Post by: z on October 20, 2009, 11:45:24 PM
@redraider147:  Hi redraider!  It's great to hear from you again.  I'm glad you like the idea of tweakable parameters - I'm really looking forward to when GoaSkin has this ready.  I think it's going to add a whole new dimension to traffic management in SC4.

As for specific bus routes, you're right - this will never be possible through the traffic simulator.  But you can actually do it right now, if you have the patience.  There are various bus blocker lots out there, and you can use them to guide where buses can and can't go.  This would have no ill effect on the traffic simulator.  Of course, where two bus routes crossed, the buses could go either way; I can't think of a way to change that.

As for bus lanes on avenues, something approximating that could be done with the bus lanes multiplier in the coming NAM Tool, although like the highway bus lanes, it would not be visible in the automata.

You will be able to tweak network capacities, but only as a group, as the relationship between the networks needs to remain the same.  And network speeds (other than buses) will not be tweakable; they affect too many other things, and there's actually an optimal value for them.



@ldog:  Please forgive me for not answering your questions directly.  However, the traffic simulator is much more complicated than most people realize, and to answer your questions properly would take many hours of work, which is time that I simply don't have.  Also, in the end there really wouldn't be much point to it.  Simulator Z has taken traffic simulator technology pretty much to its limit in SC4; minor tweaks are still possible (and likely), but as I have stated elsewhere, there's not going to be a Simulator Z 2.0.

I should point out that you have also come to a number of erroneous conclusions regarding the simulator, and once again, I must apologize for not having the time to go through them all.  However, many of your questions have already been answered, most notably earlier in this thread, but also in other places that you have mentioned looking.

Quote
Read through most of the discussion from you, Mott, Jplumbey, etc. about how the traffic sim works. I've tinkered my Z so much I suspect it looks more like A or B just with better pathfinding.

First of all, many of those older discussions were simply what was believed to be true at the time.  Where Simulator Z departs from what they say, it is due to large amounts of experimental evidence that I obtained over long periods of time.  To throw out these changes without understanding what they do is not wise.  As jplumbley has said with respect to the simulator, "Do not modify something if you don't understand the consequences of what you are changing first."  I can tell you from seeing what you say that you do not understand the vast majority of what is going on here.

What I would recommend is that you simply wait for the version of the NAM Tool that will allow you to tweak those properties of the simulator that are safe to tweak.  And if you want to do actual modding, there are many places in the NAM and elsewhere that could benefit from modding far more than the traffic simulator, which is pretty much a finished project.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 21, 2009, 02:15:35 PM
I understand that maybe this was not the right thread to post these questions but with all due respect there is no need to be a jerk about it. Expecting exactly this kind of response was why I dragged my feet for 2 weeks posting any of these questions.

I was going to post these questions in the traffic thread poll but since you requested discussion be posted here so as to not derail the poll thread any further than it has been I complied with your request. I suppose I didn't make clear my questions and my reasoning for the questions is less about Sim Z and more about the traffic sim in general. The way things are going it looks like there will only be 1 traffic simulator for the NAM.

I figured you were the person to ask but if you don't want to help me, well you certainly don't owe me or anyone else here anything.
Saying that there is no point in answering my questions, that the Z sim is the ultimate, there is nothing else that can be done with the traffic sim, that I don't have a clue what I am messing with and should just leave it to the expert (you) and toddle off and go work on some other mod is HIGHLY pretentious.

I understand plenty enough about how most of this game works including the traffic sim. Every time I make a change to the traffic exemplar I also go and make the relevant derived changes to a bunch of other files as well (the data viewer, transit switches,etc) so that everything is in tune. There is not a single piece of content that I have downloaded and used without tweaking it in some way. Most of how this game actually works I have figured out by pouring over exemplars with ilives reader. So uhh yeah, I really take offense at "you obviously have no clue what you are doing and shouldn't mess with any of it"

I am not by any means knocking all your hard work. Many of the changes you have made are brilliant. I did however realize pretty quickly though that it is designed for something completely different than what I want to accomplish. I realize I may not have phrased some of my questions very clearly but I thought most of them were pretty much yes/no or simple answers that I would expect someone who thinks they know the traffic simulator inside and out to know off the top of their head. Also while I have made every effort to be thorough in reading the 2+ years of discussion threads about the sim I know that I might have missed some relevant information because I have to skip over all the useless posts in a discussion thread. I did not find any mention of some of these things anywhere.

I have been generally happy with the results I am obtaining but I am just looking for clarification and trying to understand or make sure I understand everything properly.

Question 1 was pretty cut and dry. I am asking if "nearest destination attractiveness" is the pathfinding heuristic. I am not asking what the pathfinding heuristic is, how it works. I am not even interested in changing the value from yours since I think you hit it on the head. I simply want to know where in the exemplar it is defined because I do not see "pathfinding heuristic" in the reader.
I know you know the answer to this since you have worked with it. No hours of work here. Would it really have been that difficult to answer that question?

Question 2...well I can see how maybe you might take offense and see that as an attack on your sim, which was not my intent and if so I apologize. I am trying to determine what is the needed travel distance because my goal for my traffic simulator is just to rebalance and make the game fun but challenging. While I have some interest in realism, my personal feeling is that realism is good so long as it does not conflict with fun (if I wanted strict realism I would stay in the real world). So I have no interest in making an accurate to scale city recreation, which is what the Z sim is designed for and apparantly damn good at. Someday I will probably install the CAM and all kinds of other things that right now I have no interest in using and then yes, your sim will be the perfect sim for that. Right now it isn't. I am not asking you to redesign your sim for me. I am asking for help in designing my sim for me. I am also not looking to "compete" with you and come out and say here is my sim which is better than your sim. While I put it up for download at some point, it is only by the reasoning that if even 1 other person likes it and wants to use it then it was worth sharing but I am doing this for myself and even if noone else is interested it is still worth the effort.

Question 3 I thought was very valid and if it was mentioned in any discussion I can't seem to find it. Perhaps noone has even thought about it. Depending how the game engine handles it, it is either a very relevant question or it is completely irrelevant. Judging by the fact that you set yours to 60 that implies that you know it is irrelevant (because maybe there are way more time units in a game day, or the commute time unit has nothing at all to do with the game day time unit) OR you know it is relevant but you don't care (which I doubt) OR you don't know. Those are really the only 3 possible answers.

Question 4...ok this was kinda malformed. I went back and reread some of the relevant discussion. I pretty much understand how it works. Between what others have said and my own experimentation it is really not relevant to say "how many commuters per hour do I want passing through this network before it becomes congested" all you really need to determine is how many you want per commute (day or evening or just take whatever total you want and divide it by 2). I guess I was just looking for a bit of clarification on setting a realistic number, but really the deciding factor for me on it is how often I want to be bugged by congestion messages.

Question 5 once again, very simple question, very relevant. If each person who gets on the bus is their own bus, then having the bus generate congestion defeats the main purpose of the bus (which is to reduce congestion). That is why Maxis set them not to. That is also why they privileged the bus with extra speed (I concur with you that the bus doesn't need the extra speed as it is already privileged enough...but I am not interested in making it slower "for realism" as you did) I know somewhere you stated that you had found some suitable workaround (for the congestion effect) but you did not say what. I also can't extrapolate it from the exemplar. Being as everything else in the NAM is mostly RUL files and concerns network segments themselves leads me to the conclusion that everything about the traffic simulator that is not in the exe is contained in the single exemplar file. So you know the answer to this. No hours of work here either.

Question 6 & 7 I did not express myself well at all. My bad. Also, once again I don't have the game here in front of me at work so I may not be asking about the variables I mean to ask about, but let me try this again.

6. Since pedestrians do not generate and are not affected by traffic (in your sim, my sim, default sim, anyone elses sim that I've seen). They either are going to be affected by the lowest congestion speed factor (1.3 at 0% for example) OR they are going to completely ignore the congestion values and always run around at their stated speed. There are NO OTHER possible answers. Either you know or you don't. So all you had to do was say A, B or I don't know. Now I thought about it and I think I can pretty easily whip up a test mod to find out (do not allow any other traffic type to reach destination, see how far they walk) and maybe that is what I will do when I get home tonight.

7. While this would seem to be a no-brainer, because if you don't generate traffic then you won't count towards the congestion total obviously. That applies to a network segment. But RTMT and other stations are not network segments, they are lots. So really what I am asking is how does lot capacity work. Considering you give estimates for station cap and have pretty much taken over the RTMT as well I would expect that you this unless you are just pulling station capacity number out of your ass. While I understand this can't all be done purely by mathematics becase there are too many interelated factors to consider and in the end it all comes down to how it works out in the game you must have come at some rudimentary formula to determine station capacity vs network capacity.

Also here is not a question I posted because I know the answer but an example of why I am doing my own sim and that I do understand at least some of the relationships between values in the simulator. As you have it one-ways and avenues have no advantage over roads and therefore no usefulness under sim Z. I understand this was done in anticipation of the NWM which is why I did not pose the question. However A the NWM is not out yet and B I really have no interest in using it. My solution? I set 1-ways to have 1.5x the capacity of a road, the avenue to have 2x road capacity and about 30% higher "speed limit". This to me is a good balance. I came up with these figures on Mott's "1200 per lane, 1800 per lane unrestricted left turns". While I may vary the capacity, I always stick to this ratio. The one-way costs the same as a road (plop and maintenance) but is less flexible so therefore should have some advantage. The avenue costs way more, it also takes up 2 tiles. While the capacity should be the same as two roads, it needs some advantage still or it is a waste of money. Also 2 one-ways would still have higher capacity so the extra speed needed to be added to compensate for that as well. Going further from that a highway is 2 one-way roads but of course with much higher speed and so I worked highway cap and speed off of that. I could go further but I think you can see where I am going with this and I don't want to bore everyone.

So if you say you don't want to share your information that's fine. I'd have a lot more respect if you just said so instead of patronizing me and giving me BS about how it would take you hours of work that you don't want to do. Which I am not asking you to do either, I am pretty sure you have already done the hours of work and I was just hoping you would answer a few questions. Like I said I realize you don't owe me anything. Honestly, you have already given me a lot because I've learned a lot just comparing your values to the default values, reading your posts, etc. So let me say thanks for making the sim and sharing it, even if I don't use it.

If you don't want to continue this discussion (which I suspect you don't since you blew me off the first time) I will respect your wishes and trouble your thread no further. I would repost my questions elsewhere but it would seem to me that you really are the only one actively working on the traffic simulator so I don't expect to get answers anywhere else on this forum.
Title: Re: Traffic Simulator Z Development
Post by: z on October 21, 2009, 03:20:54 PM
OK, I'd like to meet you at least half way here.  Answering your basic questions is not difficult, as you pointed out; I can do that rather simply.  It is explaining why the decisions were made that is so time-consuming.  But I will give you the basic answers to your questions; I think other people may be interested in these answers as well.  It will have to be later today, though, when I have a bit more time.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 21, 2009, 05:39:24 PM
Steve, considering where you and I started out, I would have thought you'd be more willing to help people learn more about the Simulators.  I learned through our dealings that I made a mistake in the way I responded to you when you first started posting, you are following the same road I did.  I hope you hear this as advice and help Idog out and give him the chance I didn't give you.


1. I keep seeing the pathfinding heuristic mentioned but I cannot find it in ilives reader. I am assuming based on the values observed and in discussion threads that it is the "nearest destination attractiveness" but I just want to be sure.

It is in the Traffic Simulator Exemplar, probably about halfway down in the list of properties.  Basically, the lower the value the harder the Simulator looks for the shortest possible route, the more routes it compares.

Quote
2. If commute time is reset after leaving the tile then isn't 60 WAY overkill? The maximum trip length for a large tile is 1024 (256 up, 256 across x2). Even a maximum congested highway in Z would only need 31 time units to cross the tile and back.

Simulator Z has attempted to use realistic values to create realistic paths.  It has done it's job finding the right paths and making sure that every Sim finds a job within a realistic physical distance.  The side effect of the overkill in such a high commute time is it almost negates abandonment in the game, making it much easier to play and keep pretty looking cities.  A lot of people like this and is probably part of the reason why Simulator Z is so popular in usage, especially for MDs.  It may not completely remove abandonment in the game, but it definitely minimizes it greatly because Sims will travel everywhere no matter the congestion.  Simulator A on the other hand, which is very similar to Simulator Z in many ways has a lower commute time (still higher than the Default) but refined for a large city tile.  It works with the limits of a large city tile to keep the challenge of abandonment a part of the game for those who are not interested in "sandbox" MDs but just playing the game and more focussed on the traffic and network portions of the game.

Quote
3. Are commute time units independant from the timeclock for a sim day (and I am talking about the actual calendar day not the day/night day) ? I have not seen any mention of this anywhere. If they aren't I'm thinking that there are only 48 units in a sim day. I'm basing this off Maxis statement that "sims will only commute about 2.5 hours a day" and the default max commute of 6. Consider their "about 2.5 hrs" to actually mean 3 hrs and you get a 30 minute time unit (because I don't think that they arbitrarily picked 6). If this is the case then the max commute really should not be altered at all so speeds should be increased instead of time units?

To be honest, it is not really easy to compare the units in game to real life units.  But, let's make an example and do the math to find out the "real" travel time would be.

If we were to compare, let's use a network speed of 50 tiles per unit of time to make it easy (roughly the speed of a car in game).  Each tile is 16m in length and that would mean that a Sim would travel at 800m per unit of time.

So, what do you want to base your calculations as being the "real" value?  Do you want the 50 to mean 50 km/h?  Do you want the unit of time to equal, 1-minute, 30-minutes, 1-hour?  The reason I say that everything is unitless, is because it really can be viewed from many different points of view.  All that matters, is the number of tiles per unit of time, because that is how the game interprets it.

Just for fun, let's assume MAXIS tried to make the speed 50 mean 50 km/h.  If we reduce this to meters per minute:

50,000/60 would be 833.33 meters per minute

This makes it seem like MAXIS attempted to make the Speed and Commute Time roughly equal, km/h and minutes respectively.  That means, that the actual round-trip commute time they had in the default Simulator is 6 minutes. 

Why did they do that?

Simply put... What is the actual size of a City tile, 1km for small, 2 km for medium and 4km for large.   You physically do not have the "real" distances we have in real life travel.  So, they scaled it down to make it work in-game and make it challenging.

Quote
4. Is capacity per time unit or for total day or half the day or what? Going by (I think it was) Motts figures, let's say I want 2400 cars per hour on road. Do I figure out my commute time into hours and then multiply the capacity by that? One-ways since they are theoreticly only used half the day do I set the capacity at what I want or double it or half of it? Something that seems very simple, cut and dried actually turns out to be quite complicated.

Capacity is a difficult thing again...  It is hard to compare it to per hour, per day, etc. in real life terms.  In the game it is "per day" which is both morning and evening commutes combined.  If you had 1000 cars on the road in the morning commute and 250 cars on the road during the evening commute the total for the day for the purpose of calculating "congestion" would be 1250 cars.  So, if you had a 2500 car capacity on a given network and you had the same 1250 cars on that road between morning and evening commutes you would end up with a congestion of 50% and your Congestion vs Speed curve would act accordingly.

Quote
5. Doesn't making bus generate traffic defeat their purpose? If each sim that rides a bus still count as a vehicle then you aren't reducing the congestion any. I remember you saying you found a workaround but going through the file in the reader I could not find any variable that would seem to effect it.

I have to agree with you on this "defeating the purpose".  But, on the contrary it could be considered a "cheat" to have bus traffic not effected by congestion because it literally makes bus traffic unlimited.  To be honest, in real life, busses follow specific routes and reduce traffic.  There is no way in game to really emulate something like that.  To me they really act like a taxi service instead and if that was the case, then they really could change the skins and change the name of bus stations to taxi depots.

There is no direct "workaround" for this.  Either you add to traffic congestion or you don't, there are no ifs, ands or buts.  A possibility that Z might have used is reducing the amount of traffic created by each Sim in a building, but I don't know if that is what he has done or not.

Quote
6. Type does not generate traffic(or is it not affected by traffic? I'm sorry I am at work right now)==not affected by congestion? Or in other words: Are my pedestrians (and bus if I decouple from traffic) going to run around at 130% speed because there is never any congestion for them or are they completely unaffected by the congestion modifier?

I am not entirely sure on this one.  My assumption would be that they will run around at 100% Speed not 130% Speed because it is "unaffected by congestion".

Quote
7. If type doesn't generate traffic (i.e. peds again) should they not count against capacity (i.e. transit switches) and therefore station capacitys should never have to be inflated for the peds? (like RTMT for instance)

Transit Switches are special....  They have their own properties for "Speed" and "Capacity", but congestion works funny in them, if at all.  With all Transit Switches you will "Max" them out at roughly 10x the Capacity of the Lot, so if the Capacity equals 100, you can have up to roughly 1000 Sims passing through it.  I am not sure how the lots count Sims coming in or out of a station, there are a lot of bugs with the Transit Switches that are known, especially with how it counts Sims passing through and the numbers "counted" by the lot compared with the morning and evening commute queries, don't always align.


For those wondering, it took me roughly 1 hour interrupted by watching TV to answer the above questions.  I hope they provided some insight.
Title: Re: Traffic Simulator Z Development
Post by: z on October 21, 2009, 09:00:55 PM
Thank you for your assistance, Jason.  I write much slower than most people, so such a post would have taken me much longer.  However, my answers to a number of ldog's questions are different from yours, and as I promised him my answers, I will give them to him here.

2. If commute time is reset after leaving the tile then isn't 60 WAY overkill? The maximum trip length for a large tile is 1024 (256 up, 256 across x2). Even a maximum congested highway in Z would only need 31 time units to cross the tile and back.

Although much of what Jason said here is correct, there are a few points that he left out.  The maximum commute time, like many properties in SC4, controls more than just the maximum commute time.  Specifically, it also affects the likelihood that Sims will commute into adjoining tiles, and therefore has a big effect on intercity travel.  My experiments showed that a max commute time of 180 was necessary to get substantial intercity rapid transit, and that a max commute time of 600 was necessary to achieve the same with cars.

Interestingly, the last value is not that different from the values used in one of Tropod's simulators.  This simulator used 10x speed and 10x commute time.  As Mott showed, increasing speed is similar to increasing commute time, though it introduces other complications.  So 10x speed and 10x commute time gives the Sims the same range as 1x speed and 100x commute time, which is what Simulator Z uses.

As for the challenge of a lower commute time, such as that used in Simulators A and B, the question is a bit more complex here.  The extra "challenge" introduced here is easily overcome by placing zones closer together.  Then it's as easy to run a city as it is in Simulator Z.  But real cities usually don't have their zones always placed that close together.  That means that it's impossible to build those cities without getting widespread abandonment.  That's not a challenge, since it simply can't be done; that's a limitation.  Do we really want a game that will not allow you to build real cities, or build cities with zones spaced the way they are in the real world?

Then there's the whole question of abandonment due to commute time.  Whole neighborhoods do get abandoned, but not because their residents decide that their jobs are too far away (especially when "too far away" is defined as a 9-minute commute; see below for details).  So why did Maxis introduce this?  Most likely for the same reason they introduced a lot of features; computing power of the average PC at the time of the game's release (almost seven years ago) required limitations of this sort.  But they aren't required today.  Do we really want them for the purpose of introducing artificial challenges?  There are plenty of realistic challenges in Simulator Z, many of which are not present in other simulators.  Personally, I think that the traffic simulator should not introduce unnecessary artificial challenges into the game, when it is capable of introducing so many real challenges (such as network cost, network capacities, travel fares, etc.)

Nevertheless, if people really do want this limitation, it could always be added to the NAM Tool, so that people could set their own max commute times.  I would be interested in hearing from people on whether or not they wanted this.

Quote
3. Are commute time units independant from the timeclock for a sim day (and I am talking about the actual calendar day not the day/night day) ? I have not seen any mention of this anywhere. If they aren't I'm thinking that there are only 48 units in a sim day. I'm basing this off Maxis statement that "sims will only commute about 2.5 hours a day" and the default max commute of 6. Consider their "about 2.5 hrs" to actually mean 3 hrs and you get a 30 minute time unit (because I don't think that they arbitrarily picked 6). If this is the case then the max commute really should not be altered at all so speeds should be increased instead of time units?

The Commute Trip Max Time property is well documented and refers to the round trip commute time in minutes.  Note that when you click on it in the Reader, in the bottom panel it specifically says, "Maximum time for a commute trip in minutes."  Now you can't believe everything you read in this game, so it's necessary to do a little checking, especially since the Prima Guide (which mentions the 2.5 hour figure) directly contradicts the internal documentation.  (Hint:  In such cases, it's generally quite safe to bet on the internal documentation.)  The one thing we know for sure is that the size of a square is 16 m on each side.  Not only is this documented extensively, but you can measure the scale of large buildings to verify it.  From here, you can use experiments to verify that the speed really is expressed in kph, which I did, and which is also what the Prma Guide states.  And from there, it's a trivial step to prove that Commute Trip Max Time is the round trip time in minutes.

From Jason:

Quote
The reason I say that everything is unitless, is because it really can be viewed from many different points of view.

The experiments I have done have shown that this statement is not true; the units are as I have described them, which is consistent with the internal documentation in the game.  You can take that to the bank.

So the Maxis Commute Trip Max Time value of 6 means that Sims have exactly three minutes to get from their home to their job, door to door.  Again, the only reasonable explanation for Maxis' having done this is available computing power at the time.  The round trip figure of 2.5 hours (which is reflected to some extent in the Commute Time Graph, which was scaled specifically to show this) was devised to make things sound more realistic.  But it bears no relation to the reality of the game.

There are many reasons why you don't want to raise the speeds.  Mott mentioned some of them, including the Transit Switch Entry Cost.  But there are many others.  And there's no reason to raise speeds, when raising commute time accomplishes what you want without any side effects.

Quote
4. Is capacity per time unit or for total day or half the day or what? Going by (I think it was) Motts figures, let's say I want 2400 cars per hour on road. Do I figure out my commute time into hours and then multiply the capacity by that? One-ways since they are theoreticly only used half the day do I set the capacity at what I want or double it or half of it? Something that seems very simple, cut and dried actually turns out to be quite complicated.

What Jason said here is correct; capacity is per day.  A while ago, we all tried to figure out how long a commute period was, and we eventually gave up, because there's not enough information to determine that.  Fortunately, that information isn't required anywhere.

To be continued soon...
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 21, 2009, 11:06:21 PM
Personally, I think that the traffic simulator should not introduce unnecessary artificial challenges into the game, when it is capable of introducing so many real challenges (such as network cost, network capacities, travel fares, etc.)

I think you said it most correctly here....  Not everyone thinks the same way.  This is why we should not reduce the Simulators down to one.  And you know my feelings on the NAM Tool being used to let people change the values themselves, especially when they haven't read into things.  Simulator A and B work just fine, they are a hybrid essentially of Simulator Z and the default Simulator from MAXIS.  We all know your view that your work is the best, now you must understand that others may feel the same way about their own work too, but are still willing to accept yours as exceptional work, just something different.
Title: Re: Traffic Simulator Z Development
Post by: z on October 21, 2009, 11:58:06 PM
First, to answer Jason's recent post:  Yes, we are in at least partial agreement here, and I used the word "personally" quite deliberately.  Since Simulator Z is designed for everyone, if people don't share my opinion, then the option I mentioned can be introduced.  People here seem to really like the idea of being able to tweak the simulator's values; why not let them if it can be done safely?  There are certain ways that these tweaks can be done safely; we can discuss that on the NAM board later.  And there's certainly room for everyone in Simulator Land; if people think something's the best, or simply the best for them, then it can be made available, whether it's yours, mine, or anyone's.  Again, we have the same goal here: give the players what they want, but do it safely.  I'll be elaborating more on the NAM board soon.

And now back to ldog's questions:

Quote
5. Doesn't making bus generate traffic defeat their purpose? If each sim that rides a bus still count as a vehicle then you aren't reducing the congestion any. I remember you saying you found a workaround but going through the file in the reader I could not find any variable that would seem to effect it.

Ah, buses.  Jason summarized some of the problems inherent here.  But I've noticed that the people who've objected to having buses contribute to traffic have done so on a theoretical basis - no one has pointed out a situation where it has actually caused problems.  To the contrary, this feature is implemented in Simulator Z along with other features so that buses appear to reduce congestion.  Take the following example; the first picture is a city of two million running Simulator A at Hard capacity:

(http://img361.imageshack.us/img361/83/nssalcongie6.jpg)

And here's Simulator Z running in the same city, at the same period of time, with Low capacity, which is very similar to Simulator A's Hard:

(http://img361.imageshack.us/img361/7161/nsszlcongxc2.jpg)

There is far less congestion in the Simulator Z version of the city than in the Simulator A version, even though buses are counting towards traffic and congestion in Simulator Z and not in Simulator A.  To the user who doesn't look underneath the hood, it looks like buses have reduced congestion.  So I don't think this is a real issue.

However, it is actually possible to reduce the amount of congestion caused by buses compared to that caused by cars, for those who really want to do so.  Congestion is essentially the part of a network's volume that is in excess of the network's capacity.  But as any traffic engineer will tell you, the capacity of a network is dependent on the speed of the vehicles in the network.  So by using the Bus Multiplier in the upcoming NAM tool to raise bus speeds, their contribution to both traffic and congestion is lowered, while that of cars is unaffected.  And that's how you can do what seems to be impossible if you just look at the traffic simulator's exemplar.

Quote
6. Type does not generate traffic(or is it not affected by traffic? I'm sorry I am at work right now)==not affected by congestion? Or in other words: Are my pedestrians (and bus if I decouple from traffic) going to run around at 130% speed because there is never any congestion for them or are they completely unaffected by the congestion modifier?

Pedestrians are just like any other travel type.  However, in Simulator Z (and I believe all the other simulators as well), they are not affected by traffic, so they always move at a constant speed.

Quote
7. If type doesn't generate traffic (i.e. peds again) should they not count against capacity (i.e. transit switches) and therefore station capacitys should never have to be inflated for the peds? (like RTMT for instance)

Pedestrians don't contribute to traffic, and as a result, I'm fairly sure that they don't count toward station capacity.  But I haven't seen anything on this, nor have I tested it.  However, station capacities aren't what they seem anyway, as Jason and other will confirm.  Briefly, stations don't suffer service degradation at all (despite what the queries show) until they reach at least 400% of capacity (it varies by station in a way that has yet to be determined), at which point they simply stop accepting passengers for the day.  Pedestrians don't seem to play a big role in this process.

As for one-way roads, once again, capacity is determined by speed.  In RL, one-way roads have higher effective capacities than two-way roads with the same speed limit because they don't have the same slowdown at intersections; sometimes they're assisted by timed stoplight cycles.  Neither of these options is available to us in SC4.  However, the fact that volume is calculate on a per-commute time basis while capacity (and congestion) are calculated on a per-day basis means that anywhere that traffic on two-way roads is at all asymmetrical during either commute period, putting in pairs of one-way roads will increase the total effective capacity, even though the nominal capacity is the same.  And in most cases, I've noticed that the effective capacity is increased by about the same amount that it is in RL.  I initially didn't like having to make the nominal capacities of one-way and two-way roads the same just because of NWM, but once I saw how this worked, I realized that it was the right thing to do, regardless of whether or not NWM ever existed.

Please understand that I have no objections to sharing my information - to the contrary, I think it would be wonderful if everyone understood everything about how Simulator Z worked.  It really is simply a time issue for me.  In retrospect, I should have given you brief answers to your questions; I hope that these posts have given you what you wanted.
Title: Re: Traffic Simulator Z Development
Post by: k808j on October 22, 2009, 12:08:16 AM
We  ()borg() have been very much educated on Sim Z from this particular discussion and appreciate everyones
comments

BTW good job on the RTMT 3.60 release Z.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 22, 2009, 11:28:08 AM
Z and J, thank you both for replying.
You did go into far more detail than I was expecting, and I can certainly respect your time. I know I just never seem to have enough time for everything I want to do.
I really do wish I had started playing like a year ago when these discussions were current, I'm sorry if it seems like beating a dead horse or just rehashing old conversations.
So thank you (and you as well J) for all the time put into that.
It certainly helps clear up a lot and has given me much food for thought.

Of course I still have some questions...

Still can't find any variable defined as pathfinding heuristic. Is it maybe reader version difference? As I've said I am fairly certain the var defined as "nearest destination attractiveness" IS the pathfinding heuristic y'all keep referring to. The values in the various sims vs what is said in the discussion threads would support that. I'm sorry if I'm being dense and they actually mean the same thing. Like I said, I'm comfortable with it, just looking for confirmation.

Although some of what I've asked I thought it was just that my wording was bad but J really made it very clear to me that I was thinking about things in the wrong kind of context. When I was speaking in terms of the "2.5 hour commute" I know that it isn't 2.5 hours of course. I was speaking of it in the way the game is trying to present it to us, even though under the hood it really has nothing to do with it.

What I was trying to say is taking the 6 time unit x 25 display multiplier = 150 minutes max commute (yes I know it is nonsensical please bear with me...I also strongly suspect the display multiplier doesn't actually work). I was then saying they fudged it, probably for display purposes (by their graph noone will ever go to a 1.0 commute, which if you inject reality makes sense...it is possible for example to commute 4,5,6 however hours a day, and believe me I have known some people who lived out in the boonies that drove 3 hours each way to work but I sure as hell am unwilling to do it) and a time unit was actually 30 minutes. So then there would be 48 time units in a sim day IF the traffic sim time was directly related to the game day time. So that was how I arrived at that (mis)conclusion.

So what you are saying Z, is that the game day is actually 1440 time units (1 time unit is 1 minute).
And J, although it is technically inaccurate to say it is unitless, I understand what you mean by it. That really does sum up why I am asking these questions; I am trying to define the units.

On #2 , according to your observations, logic would dictate that the commute time does NOT get reset when you leave the tile. If the commute time got reset everytime you changed tiles then all you need to do is get off the current tile and you can do another full trip. So now I'm more confused.

In regards to abandonment, what about the mod that reduces that? I've been playing with it a bit but I have only poked under the hood slightly. My thinking though is that tweaking those values in tandem with the traffic sim can tune the abandonment factor more finely than trying to do it by the traffic sim alone. Once again Z, don't think I am trying to get you to change your simulator to suit me, I just think it is easier to answer my questions if you understand my reasoning. I also chose you to "pick on" I guess because when I installed the NAM, the documentation led me to believe that all the other sims were old and outdated and that z-sim was the general purpose controller. Naturally that is the one I popped in and so that is where most of my comparisons come from. I will unpack and start looking more closely at the other traffic sims this weekend as well.

I understand the capacity better now, thanks to both of you. Very wierd the way Maxis did that (congestion and volume both should have been for evening/night or both per day but not seperated) but the old adage of "change the things you can change, accept the things you can't" really applys. I'm working on the "have the wisdom to know the difference" part. At any rate, this goes along with one of those things to just not try to put into reallife terms and just go with values that "feel right".

#5 Isn't a valid comparison. The only way to get an apples to apples comparison would be to take the same traffic sim and run it once with buses not adding to congestion, and again with buses adding to congestion. Like you've said, there is a lot more to it than just capacity. Again, don't take any of this as a personal attack, you are happy with the way you are handling it then that is all that matters as far as your simulator is concerned so don't feel like you have to defend yourself or your reasoning.

I'm sorry I'm so longwinded, once again thank you both for the time and discussion.

On an unrelated note: I made a real boner 2 nights ago. Somehow I got an extra copy of the traffic sim in the nam plugins (probably careless dragging and dropping), I also because of the fact that I have been putting in and taking out pieces of the NAM (I decided I wanted the road turnlanes in so I had to run the evil installer again) so I moved and renamed your traffic controller and data plugin to my own directory. Well let me tell y'all the game will run still but it crashes constantly. I couldn't figure out why I kept getting extra subway tubes in the menu (because I agree with and kept your more expensive subway segments). The moral of this story, it was EXTREMELY good advice to do your testing with a clean plugins directory and it was pretty stupid of me to disregard that advice. So needless to say a lot of my prior testing is invalid.




Title: Re: Traffic Simulator Z Development
Post by: Tarkus on October 22, 2009, 02:08:21 PM
I also because of the fact that I have been putting in and taking out pieces of the NAM (I decided I wanted the road turnlanes in so I had to run the evil installer again

Try using the Mac version of the NAM instead, if you're planning on tinkering with different plugins a bunch.  It's basically just a .zip with all the files inside, sans installer.

-Alex
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 22, 2009, 02:55:18 PM
Try using the Mac version of the NAM instead, if you're planning on tinkering with different plugins a bunch.  It's basically just a .zip with all the files inside, sans installer.

-Alex

Well that would have never occurred to me.  &idea
Thanks for the tip :thumbsup:
Title: Re: Traffic Simulator Z Development
Post by: z on October 22, 2009, 03:42:20 PM
Still can't find any variable defined as pathfinding heuristic.

Depending on how your version of the Reader is set up, it may appear as "Nearest Destination Attractiveness."

Quote
So what you are saying Z, is that the game day is actually 1440 time units (1 time unit is 1 minute).

Yes, although we don't know how much of that forms a commute period.

Quote
On #2 , according to your observations, logic would dictate that the commute time does NOT get reset when you leave the tile. If the commute time got reset everytime you changed tiles then all you need to do is get off the current tile and you can do another full trip. So now I'm more confused.

No, commute time is completely reset when you leave the tile.  What I was saying was that the value of the maximum commute time affects the probability that the Sims will leave the tile.

Quote
In regards to abandonment, what about the mod that reduces that? I've been playing with it a bit but I have only poked under the hood slightly. My thinking though is that tweaking those values in tandem with the traffic sim can tune the abandonment factor more finely than trying to do it by the traffic sim alone. Once again Z, don't think I am trying to get you to change your simulator to suit me, I just think it is easier to answer my questions if you understand my reasoning. I also chose you to "pick on" I guess because when I installed the NAM, the documentation led me to believe that all the other sims were old and outdated and that z-sim was the general purpose controller. Naturally that is the one I popped in and so that is where most of my comparisons come from. I will unpack and start looking more closely at the other traffic sims this weekend as well.

My experience with these mods is that they cause unpredictable complications with the traffic simulators, and with the game in general.  With Simulator Z, they are definitely not necessary, as long as you build your city well.

The NAM documentation on Simulator Z is quite accurate and backed up by lots of experimental evidence.  Simulator Z was built using the lessons and technology learned from previous simulators, plus a lot of original research.  But how you interpret that is completely up to you.
Title: Re: Traffic Simulator Z Development
Post by: tamorr on October 22, 2009, 04:16:17 PM
   From what I understand of the simulator Z, I usually call it "Divide and Conquer" as per the decription that you gave when you were developing Z. What I mean by that term is the relavent dividing of Mass transit. Saying that sims will even spread among the various types, which is why I enjoy the simulator.
   Also I know I mentioned long ago in another post that I went from better pathfinding simulator, which definately reduced traffic by that meathod when I switched to medium Z. I am right in saying that the simulator did indeed evenly distributed the sims, per say to the many Mass transit sytems?
  I may not phrase things well but that is what it appears to me from all the explainations I have gone through since the Z was being proccessed. Anyways thank you for making a great simulator. :)
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 22, 2009, 04:34:27 PM
On #2 , according to your observations, logic would dictate that the commute time does NOT get reset when you leave the tile. If the commute time got reset everytime you changed tiles then all you need to do is get off the current tile and you can do another full trip. So now I'm more confused.

If the "clock" never got reset there would never be a problem with the Eternal Commuter Circles.  ::)
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 22, 2009, 05:10:24 PM
Depending on how your version of the Reader is set up, it may appear as "Nearest Destination Attractiveness."

THANK YOU!!!

Yes, although we don't know how much of that forms a commute period.

Well it should be however many time units you set for max commute if they are one and the same. (Or half of it if you are refering to commute period as evening OR morning commute)
I guess you could make them commute all day if you set it to 1440 and if you set it above that the game should crash *shrugs* I may have to go try that just to see if I can make it BSOD but I think tonight I am going to go and do the bus test (adds traffic/doesnt add traffic) myself. I will let you guys know the results.

No, commute time is completely reset when you leave the tile.  What I was saying was that the value of the maximum commute time affects the probability that the Sims will leave the tile.
AND
If the "clock" never got reset there would never be a problem with the Eternal Commuter Circles.  ::)
Great, another factor. So pretty much for everything that is pinned down in the traffic sim there is another thing (or 2 or 3) that are still best guess huh?
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 22, 2009, 05:32:57 PM
Great, another factor. So pretty much for everything that is pinned down in the traffic sim there is another thing (or 2 or 3) that are still best guess huh?

There is always something else that is effected by what ever decisions you make.  That is why it is so important for you to understand what you are changing before you change it, because then you can watch for those side effects.  On the other hand there is always something else to learn about and there are many things that have not been fully tested yet.  Best guesses are the element of the so-called "experts", I think for us it's more like pray and hope it doesnt screw things up too bad...  :D
Title: Re: Traffic Simulator Z Development
Post by: z on October 22, 2009, 05:45:46 PM
THANK YOU!!!

You're welcome.

[About the length of a commute period]
Quote
Well it should be however many time units you set for max commute if they are one and the same. (Or half of it if you are refering to commute period as evening OR morning commute)
I guess you could make them commute all day if you set it to 1440 and if you set it above that the game should crash *shrugs* I may have to go try that just to see if I can make it BSOD but I think tonight I am going to go and do the bus test (adds traffic/doesnt add traffic) myself. I will let you guys know the results.

I doubt it.  The SC4 simulation is a fairly primitive one, and in general is fleshed out only where it needs to be (and often not even then).  Once you go above a value of 600 for maximum commute time, the game starts slowing down a lot.  (Which really doesn't make any sense, since no one travels that long anyway.)  If you set that value high enough, you certainly might get a BSOD, but I doubt it would be at all related to the number 1440.  There's no need for the commute engine to know how long a day is, so I doubt that it does.

Quote
Quote from: jplumbley on Today at 02:34:27 PM
If the "clock" never got reset there would never be a problem with the Eternal Commuter Circles.   ::)
Quote
ANDGreat, another factor. So pretty much for everything that is pinned down in the traffic sim there is another thing (or 2 or 3) that are still best guess huh?

I think that the vast majority of the important stuff is well understood at this point (although in varying degrees by various people).  The less important stuff - that which has little impact on game play - is less understood because, well, it's less important, and our resources are finite.  What Jason said in his quote is certainly true; how does that lead to your "best guess" comment?

I see that Jason has posted while I've been slowly writing this:

There is always something else that is effected by what ever decisions you make.  That is why it is so important for you to understand what you are changing before you change it, because then you can watch for those side effects.  On the other hand there is always something else to learn about and there are many things that have not been fully tested yet. 

I agree 100% here.

Quote
Best guesses are the element of the so-called "experts", I think for us it's more like pray and hope it doesnt screw things up too bad...  :D

I'd just like to add that extensive and systematic testing can greatly reduce the need for hope and prayer.  ;)
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 22, 2009, 05:51:25 PM
Best guesses are the element of the so-called "experts", I think for us it's more like pray and hope it doesnt screw things up too bad...  :D

LOL. Yeah, I suppose the only way we will ever find concrete answers to some questions is to track down and kidnap the Maxis programmer who wrote the code. I'm sure a lot of answers are hidden away in the executeable.

Ok so I'm setting up my test case. Being as my mod is really untested and in light of recent discussions I need to rethink and overhaul some things I am going to build a city and run it for a bit with A hard. Then I am going to save, quit, cause bus to generate traffic and go back in and run it a few years. Time permitting I will also do the same 2 tests with Z low as well. To be honest I don't think it really matters which simulator I do it with but as I pointed out above it needs to be the exact same simulator only with the 1 variable changed.

Should I start a seperate thread or is it ok to still clutter yours Z? I will of course provide screenys...now who is going to provide the beer? :P

Title: Re: Traffic Simulator Z Development
Post by: ldog on October 22, 2009, 05:58:41 PM
[About the length of a commute period]
I doubt it.  The SC4 simulation is a fairly primitive one, and in general is fleshed out only where it needs to be (and often not even then).  Once you go above a value of 600 for maximum commute time, the game starts slowing down a lot.  (Which really doesn't make any sense, since no one travels that long anyway.)  If you set that value high enough, you certainly might get a BSOD, but I doubt it would be at all related to the number 1440.  There's no need for the commute engine to know how long a day is, so I doubt that it does.

I think that the vast majority of the important stuff is well understood at this point (although in varying degrees by various people).  The less important stuff - that which has little impact on game play - is less understood because, well, it's less important, and our resources are finite.  What Jason said in his quote is certainly true; how does that lead to your "best guess" comment?

I'd just like to add that extensive and systematic testing can greatly reduce the need for hope and prayer.  ;)

Well then so that brings us back to square 1 and the commute trip unit is not a minute or any other measure of time for that matter.
It would be just 1 unit of time in the traffic simulator. What I am getting at is (and yes, this goes with what J said earlier) is that it is "unitless" as far as trying to relate it to realtime, because it doesn't exist outside the traffic simulator.

It is a best guess because we know there is an effect but we don't know specificly what it is. You know that it impacted intercity commuting but you can't break it down to a mathematical formula therefore it is a best guess or guestimate as one of my old professors used to say.

I certainly agree with extensive and systematic testing as well, and I intend to do some :D
 
Title: Re: Traffic Simulator Z Development
Post by: z on October 22, 2009, 11:58:08 PM
LOL. Yeah, I suppose the only way we will ever find concrete answers to some questions is to track down and kidnap the Maxis programmer who wrote the code.

I'm not sure that would help...  ::)

Quote
Ok so I'm setting up my test case. Being as my mod is really untested and in light of recent discussions I need to rethink and overhaul some things I am going to build a city and run it for a bit with A hard. Then I am going to save, quit, cause bus to generate traffic and go back in and run it a few years. Time permitting I will also do the same 2 tests with Z low as well. To be honest I don't think it really matters which simulator I do it with but as I pointed out above it needs to be the exact same simulator only with the 1 variable changed.

It matters a lot which simulator you use.  I had to make a lot of modifications to Simulator Z to allow it to support adding buses to traffic; as far as I know, it's the only simulator where this can be done.  Before the modifications, adding the buses made congestion far worse in many places, completely exceeding the ability of the traffic simulator to handle it.

There's also so much about testing traffic simulators in general that needs to be understood; I'll summarize just the most important points here.  First, the pathfinder is the most important part of the simulator being tested here, and as the complexity of possible paths rises exponentially with the size of the tile, you need to test on a large tile filled with paths and Sims (at least a million Sims, preferably more) in order to get really meaningful results.  (On small and medium tiles, differences between most things related to the traffic simulator are much more difficult to see, and often vanish into the noise.)  You also need to try a variety of configurations (i.e., cities); some things show up only in certain configurations, and the pathfinding algorithms are complex enough that it's almost impossible to predict what those will be.  Finally, you need to do extensive regression testing (absolutely crucial!) to understand what side effects may be occurring.  Otherwise, your test results don't tell the whole story, and can end up being quite misleading.

You also have to run things for more than a few years; eight years is the minimum on a built-up large tile, and longer is better.

To do this properly will take many, many hours, assuming you already have a fair number of large test cities built.  If you don't, you'll need to add the time required to build them from scratch up past a million Sims.

I'm not quite sure why you're doing these tests.  It sounds to me like you're doing what I've already done, and I could certainly just tell you my results.  What exactly are you trying to find out that you don't think is known?

Quote
Should I start a seperate thread or is it ok to still clutter yours Z? I will of course provide screenys...now who is going to provide the beer? :P

I think a separate thread would probably be good at this point, as this is getting a little off-topic for this one.  But you can certainly answer my last question here.

Well then so that brings us back to square 1 and the commute trip unit is not a minute or any other measure of time for that matter.
It would be just 1 unit of time in the traffic simulator. What I am getting at is (and yes, this goes with what J said earlier) is that it is "unitless" as far as trying to relate it to realtime, because it doesn't exist outside the traffic simulator.

If you follow what I said before, once you see that a square is 16 m on a side, then the unit of time is a minute.  Now of course the squares aren't really 16 m long, but this is all done to scale, and "minutes" fit on this scale perfectly, along with "kph".

Quote
I certainly agree with extensive and systematic testing as well, and I intend to do some :D

OK, I'll be looking forward to the results of your regression testing.  ;D
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 23, 2009, 01:19:33 AM
Wow uh...yeah...I just thought I would poke my head out before I went off to bed.
It is taking me quite some time. No, I don't have any very built up citys to use and building one is pretty time consuming.
Since my last post I've only built one to 100k (I did pop into the one I was working on last night to see how it worked with A-hard, of course it was a bad idea to go back to this city after removing my Ind-jobs mod (which uses the recommended settings out of the CAM). Massive abandonment. LOL

Now I didn't have any abandonment problems since I rebuilt the city using A from the start although let me tell you it works very diferently from mine even though they seem closer in many values. One thing I did pick up pretty quick is that A hates the bus. My entry cost for this test is .02 which is actually .96/48 hmmm...how did I get that number...oh...yeah..J's bus speed on street was 35, which gives .027 and I just decided to round it down for some reason. Anyway that should work fine. Of course A has a much higher starting cost for car prefered (his is 1.75, mine was .1 I'm sorry I forget what yours was and I don't have it handy at the moment) and then the bus speed is slightly slower so he has depriveledged the bus quite a lot. Now I know when I was playing with Z-low they love the bus.

Thanks for the tips.

At the moment I am testing just because I want to see what kind of difference bus adding to congestion vs bus not adding to congestion makes. If you have detailed data you want to share I'd love to see it but your last example of a screenshot of 2 different simulators that work very differently from each other is not the answer I am looking for.

Of course now the idea has formed that I should test all the traffic simulators, not just about the bus thing but about how they work overall and do a comparison. One thing you have to remember is that for you people who have been playing for years the accumulation of downloaded content was a slow ongoing process. For someone walking in right now like myself there is a staggering amount of things to see and do on this forum. I've only been playing with this game for around a month I think. I spent a few days learning to play on vanilla and then that would have been it for the game. Then I started downloading content, which of course broke my game and so started the process of me finding out why all these wonderful things I downloaded broke my game. There's dependencies to download. There's conflicts to eliminate. There are things that will look like they are working but totally run your city down the drain because the values weren't set on them properly. All these things I'm sure you know very well and came gradualy over time. I've been trying to cram several years of other peoples development into a crash course just so I can figure out what I can and can't play with.

If you mean why everything in general about testing the traffic simulators? Probably the same reasons you did. Partly because I'm looking for a simulator that "feels right" for me. Partly just to learn to how it all really works under the hood. Partly just because moding in general interests me. I am not looking for a sandbox mode to make to scale realistic citys. I personally find the game is far too limited for that to be any fun. The region play is so half-assed that I find the prospect of developing 100 large tiles just to make a decent cross section of an actual metropolitan area to be about as fun as a root-canal. All I am looking for is game balance. But as I have found in many other games my idea of game balance is contrary to what is popular so modding has pretty much become a way of life for me. I know that I am creating much more work for myself (for instance instead of just dropping in the very interesting update to the RTMT I have to wait until I have a chance to tear through it and make it work with whatever I am doing at the moment) but to be honest if I wasn't I would have shelved the game already and moved on.

So my goal right now is understanding the rules (of the traffic sim) so that I can bend them to do what I want. Pretty much the same as any of the rest of you who mod.

I understand what you are saying about the scale and so the time unit is 1 minute although that would still only be correct if your speed matches..if you set the speed to something else then your time is no longer a minute. I think...getting sleepy so brain might not be working properly. For arguments sake I'll say you did the rest of the math and I agree with you.

You still don't get my original question about time though...trying to think how to phrase this better maybe. Considering how many attempts it took me to get the pathfinding heuristic question answered this could take a lot of time.  ;)

Let me break down a few things then. We have several units of time we are dealing with. There is the day and night cycle of the game which makes up a day. However we both know damn well that that is just like the automata; it is eye candy and has nothing to do with what is actually going on under the hood. This is easily proven by pausing the game and watching day and night change. Ok so far? Good.

Then we have units of time in the traffic simulator which I think we can all agree are called "commute time units". One could say that the "commute day" is 6 or 17 or 60 or whatever value you set "commute trip max time" to units long (again for arguments sake I'm going to say I agree with you and call them minutes). The commute day in Vanilla is 6 minutes, in Z it is 60 minutes (I know you keep throwing 180 out there but the version I downloaded it was 60) in A it is 17 minutes.

Next we have the game day. It is the time that it takes for the calendar date to advance by 1 day in the game. We know it takes some period of time. I don't have a clue what it is.

What I was asking was A: If any of you know how long a "game day" is and B: does the "game day" have anything to do with the "commute day"

Now what I have gathered from the discussion and general observation is that no, they have nothing to do with each other. So it's a moot point at this point. To me it is(was) a very basic and important question because if they were relative it makes a great deal of difference changing the max commute time.

Anyway, yes you are certainly right it is going to take me quite a bit of time to have any results to share.
Title: Re: Traffic Simulator Z Development
Post by: z on October 23, 2009, 02:50:22 AM
At the moment I am testing just because I want to see what kind of difference bus adding to congestion vs bus not adding to congestion makes. If you have detailed data you want to share I'd love to see it but your last example of a screenshot of 2 different simulators that work very differently from each other is not the answer I am looking for.

I understand - I was just trying to show relative appearance.  But that doesn't answer the question you're asking here.  I did those tests, but unfortunately, I did not keep screenshots of them.  However, the results can be summarized as follows:  In simulators other than Z, traffic congestion shoots up dramatically on major routes; overall congestion gets much worse.  It was bad enough that I thought that this feature would never work.  However, eventually I did get it to work.  The result was that in Simulator Z, congestion was the same whether or not buses contributed to traffic.  How can this be?  Investigation showed that the pathfinder simply spread out traffic a bit more to reduce congestion, and did it in a way that wasn't noticeable.  The Z pathfinder is set to be very smart, so this wasn't hard.

Quote
Of course now the idea has formed that I should test all the traffic simulators, not just about the bus thing but about how they work overall and do a comparison.

Here I can help you a lot more.  It is generally acknowledged (including by Jason) that Simulators A and B are very similar in their performance.  I have also verified this myself.  So I did extensive comparisons of Simulator Z against Simulator A, and recorded the results in this post (http://sc4devotion.com/forums/index.php?topic=5382.msg204681#msg204681).  This is an extremely important post, as it graphically illustrates all sorts of comparisons.  And although the title says it's the Beta 1 version of Simulator Z, no bugs were ever found in it, so it eventually became the release version.  The version of Simulator A that I tested against is the one currently in use.  You may also find the post following that one useful as well; it's a report from my main tester.

Quote
What I was asking was A: If any of you know how long a "game day" is and B: does the "game day" have anything to do with the "commute day"

What you're calling a "game day" is a somewhat arbitrary unit of time, especially since you can speed it up and slow it down.  You are correct in that it has nothing to do with the commute day.

But here's a surprise:  There actually isn't a commute day!  The Sims don't go from their houses to work and back every day or every time period or whatever.  They never go anywhere.  The game simply calculates what things would be like if they did, and then uses those calculations at various other places in the game (such as the automata).  But the traffic simulator just calculates a set of paths every few months, and leaves it at that.  No commuting actually happens.  For more details on this, you can see this post (http://sc4devotion.com/forums/index.php?topic=2763.msg177981#msg177981).
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 23, 2009, 01:09:29 PM
I understand - I was just trying to show relative appearance.  But that doesn't answer the question you're asking here.  I did those tests, but unfortunately, I did not keep screenshots of them.  However, the results can be summarized as follows:  In simulators other than Z, traffic congestion shoots up dramatically on major routes; overall congestion gets much worse.  It was bad enough that I thought that this feature would never work.  However, eventually I did get it to work.  The result was that in Simulator Z, congestion was the same whether or not buses contributed to traffic.  How can this be?  Investigation showed that the pathfinder simply spread out traffic a bit more to reduce congestion, and did it in a way that wasn't noticeable.  The Z pathfinder is set to be very smart, so this wasn't hard.

After having some time to think more about it (and probably more importantly get some sleep) I do realize it is a lot more complex than just "the congestion on this segment the buses run along will change if you toggle them causing congestion on or off". Indeed the engine is going to recalculate every single stinkin route for everything because of the domino effect. So I understand what you are saying.

Here I can help you a lot more.  It is generally acknowledged (including by Jason) that Simulators A and B are very similar in their performance.  I have also verified this myself.  So I did extensive comparisons of Simulator Z against Simulator A, and recorded the results in this post (http://sc4devotion.com/forums/index.php?topic=5382.msg204681#msg204681).  This is an extremely important post, as it graphically illustrates all sorts of comparisons.  And although the title says it's the Beta 1 version of Simulator Z, no bugs were ever found in it, so it eventually became the release version.  The version of Simulator A that I tested against is the one currently in use.  You may also find the post following that one useful as well; it's a report from my main tester.

Thanks. I had read that discussion, but I needed a reminder that it was there. It actually does save me a lot of trouble. Indeed I have been going back over and rereading a lot of the earlier discussions because now knowing a bit more about what is being discussed makes what I am reading more understandable. It is also becoming easier to figure out the timeline a bit and sort which are things that have been proved or disproved. The hardest thing about getting good information around these forums is the fact that there are years of relevant posts to go through and one has to very carefully check the dates of the posts they read; especially when you are comparing multiple threads about similar topics.

What you're calling a "game day" is a somewhat arbitrary unit of time, especially since you can speed it up and slow it down.  You are correct in that it has nothing to do with the commute day.

But here's a surprise:  There actually isn't a commute day!  The Sims don't go from their houses to work and back every day or every time period or whatever.  They never go anywhere.  The game simply calculates what things would be like if they did, and then uses those calculations at various other places in the game (such as the automata).  But the traffic simulator just calculates a set of paths every few months, and leaves it at that.  No commuting actually happens.  For more details on this, you can see this post (http://sc4devotion.com/forums/index.php?topic=2763.msg177981#msg177981).

 ??? You can go from paused to cheetah, but that does not change how long it takes the game to advance 1 day, it only changes our perception of it. Or to put it another way how it relates to the real world of the player but it does not change internally how long it takes (relative to everything else in the game).

Read that post too, also a very good read and worth rereading. Really when you think about it in those terms; basicly NOTHING ever happens in the game LOL.
There aren't even any sims for that matter (compared to say Children of the Nile where the automata actually are "real" in the sense of how they interact with the game engine). It is all a kind of smoke and mirrors trick to make it look like there is a game. There is no game. Very Zen.

You're right of course. Although of course now I wonder just exactly what is the interval for traffic engine updates. I know you said 4 months in that post but it surely must be more often than that. I am just trying to get my head around things from the ground up.

So to add more to my "why" I can say what started as "what can I do with the traffic simulator to improve my game" has turned into "what can I do with the traffic simulator, just to see what can I do with the traffic simulator". I am finding the traffic simulator itself is very interesting.
Title: Re: Traffic Simulator Z Development
Post by: z on October 23, 2009, 04:50:09 PM
After having some time to think more about it (and probably more importantly get some sleep) I do realize it is a lot more complex than just "the congestion on this segment the buses run along will change if you toggle them causing congestion on or off". Indeed the engine is going to recalculate every single stinkin route for everything because of the domino effect.

That's close, but there is no domino effect.  Instead, the finite state machine runs in parallel, computing new routes across the game based on old routes.  The results of the new route calculations don't affect the calculations of other routes in the same pathfinder run.  However, in order to avoid the herding effect, where the pathfinder would independently decide that the same route is best for lots and lots of Sims, thereby ending up with a lot of congestion on that route, the pathfinder will only increase the amount of traffic on a given route by a certain amount during any given run.  As a result, when major changes are made (such as switching simulators), it will take about five years for the traffic simulator to complete its rerouting, with the delayed routing part happening in chunks approximately 11 months apart.  This shows up as a staircase effect on the Traffic Volume Graph.  Combined with the route invalidation and adjustment that happens before this period, you get the eight years that I mentioned earlier.

Meanwhile, although many routes remain uncalculated during this time, the Sims still have jobs, and the query tool simply shows their old routes.  Yet at the same time, the volume will be shown realistically (which may as low as zero) on the affected networks.

Quote
??? You can go from paused to cheetah, but that does not change how long it takes the game to advance 1 day, it only changes our perception of it. Or to put it another way how it relates to the real world of the player but it does not change internally how long it takes (relative to everything else in the game).

True, but the vast majority of the time is just spent running the automata all over town.  There are obviously various other things that happen other than the traffic simulator, but they typically don't take much time.  That's why cheetah mode can run so fast.

Quote
You're right of course. Although of course now I wonder just exactly what is the interval for traffic engine updates. I know you said 4 months in that post but it surely must be more often than that. I am just trying to get my head around things from the ground up.

It's easy to verify that traffic simulator runs are many months apart; the effect is most obvious, once again, in large cities.  If you run your city in Cheetah mode, you'll notice that every few months the game slows down.  That's the traffic simulator kicking in.  There's a more precise way of seeing exactly when it runs, and again it works best in large cities.  Use the route query tool to check the volume of a number of routes.  When the traffic simulator runs, most of these volumes will change at least a little bit.  But you'll find that they don't change at all for months at a time, because the traffic simulator doesn't run then.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 23, 2009, 06:04:43 PM
 &idea Oh wow, that last post really made things click.
I know you are reiterating what you said in http://sc4devotion.com/forums/index.php?topic=2763.msg177981#msg177981 which I did read a few weeks before I made my first post. The problem was that then I was really not in a position to understand the impact and implications and the sheer volume of information I was trying to go through just made it impossible to digest it all clearly (not to mention I was putting myself through a lot of sleep deprivation).

Also like I said above having gone back and reread those 2 posts you linked as well as a few others, and also reading some of the linked posts that I hadn't read as well I did gain a lot more understanding. I can also see why some of my questions didn't seem to make much sense...sometimes I can be a little dense...but I also try to look at things from a lot of different angles.

Z, thanks for indulging me. Thank you Jason for taking an interest as well. I have actually learned quite a lot more with our few days discussion than I could have alone with the editor in weeks.

I've also got some great ideas that are starting to form into a more concrete plan of how to proceed. But right now I've got quite a bit of reading to catch up on so it'll probably be a while before I bug you with anymore questions  :D
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 23, 2009, 07:40:30 PM
One thing I did pick up pretty quick is that A hates the bus. My entry cost for this test is .02 which is actually .96/48 hmmm...how did I get that number...oh...yeah..J's bus speed on street was 35, which gives .027 and I just decided to round it down for some reason. Anyway that should work fine. Of course A has a much higher starting cost for car prefered (his is 1.75, mine was .1 I'm sorry I forget what yours was and I don't have it handy at the moment) and then the bus speed is slightly slower so he has depriveledged the bus quite a lot. Now I know when I was playing with Z-low they love the bus.

Alright, I have done a couple things that may affect this a little bit.  First was I cut both Car and MT preffered penalties from 1.7 to 0.85.  This shouldn't change much, but may allow more "Car Preferred" traffic to take the bus and more "MT Preferred" traffic to take the car, which in esence may just balance out and do nothing really.  The second thing I changed was the speeds of buses, and I equalized them on all networks to Cars.  This will make it so there is no preference from speed either way.

So, attached is a test version for ldog and whoever else would like to test it and see if it promotes more bus traffic.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 23, 2009, 08:19:27 PM
Alright, I have done a couple things that may affect this a little bit.  First was I cut both Car and MT preffered penalties from 1.7 to 0.85.  This shouldn't change much, but may allow more "Car Preferred" traffic to take the bus and more "MT Preferred" traffic to take the car, which in esence may just balance out and do nothing really.  The second thing I changed was the speeds of buses, and I equalized them on all networks to Cars.  This will make it so there is no preference from speed either way.

So, attached is a test version for ldog and whoever else would like to test it and see if it promotes more bus traffic.

Cool I'll give it a whirl. Although like I told you in PM, I really don't think it was inappropriate that they hated the bus. As Z points out my 100k pop city is not a proper testbed for anything yet.

Also as it is past time for Z to show us the door for being offtopic and he has really been a good sport about it, I went ahead and started a new thread:
http://sc4devotion.com/forums/index.php?topic=9179.0

Please Z, J and anyone else interested don't be a stranger, drop in and leave your comments.
Title: Re: Traffic Simulator Z Development
Post by: z on October 25, 2009, 10:28:18 PM
And now we return to our regular programming. :)

I've mentioned earlier how the NAM Tool is going to have many options for adjusting parameters that are safe for players to adjust.  Some of these are more important than others.  One of the most important is the Bus Multiplier, which will affect the proportion of buses to cars in cities.  In Simulator Z, Sims will pretty much automatically use any rapid transit that is built, since it's generally the fastest form of travel.  This is one way that mayors can differentiate, for example, American cities from European ones.  But right now, there's no way for the player to adjust the proportion of buses to cars.  The Bus Multiplier feature will solve that.  However, what's the ideal value of the Bus Multiplier for a typical European city?  The NAM Team is currently looking into revising the traffic simulator selection process by using a wizard-style interface.  So, for example, you would specify whether you were going to be building American or European style cities, and not have to worry about the Bus Multiplier.  For this to work, I need to know what's considered fairly standard for a European-style city, and I ask your assistance in determining this.  Attached to the bottom of this post is the first release of

Simulator Z - The European Version

I would appreciate it if people building European-style cities (especially Europeans :)) would give this simulator a try and let me know what they think of the bus usage.  If you think it's somewhat off, please try telling me by about how much, and in which direction.  Also, if people in other parts of the world think that a different setting is needed for their region, please let me know, and please give me an idea of what seems right (i.e., 20% more buses, etc.).  We are trying to make as many choices available as possible in as simple a way as possible.

An interesting property of the European version is that while buses still contribute to traffic and congestion, they now do so less than cars.  It's very much in the spirit of this simulator.



And now for something completely different.  Some people have found that Simulator Z (Low) is too easy for them, and they want something more challenging.  For these daring souls, I present

Simulator Z Classic

This version of Simulator Z has the low capacities of the original Maxis simulator, but without the bugs.  The capacities have been adjusted slightly so that the simulator is completely compatible with NWM; it is compatible with RHW as well.

Since the bugs in the original Maxis simulator are not present here, you no longer get situations where users exclaim, "My Sims are so stupid, they couldn't find a job if their lives depended on it!"  Instead, if you run this in a big city, you get traffic jams.  Big traffic jams.  HUGE traffic jams.  In fact, this simulator allows you to create the worst traffic jams of any traffic simulator in SC4.

Why is this?  In all the other low capacity simulators, excessive congestion leads to abandonment.  So you can't have really big cities with low capacity simulators; Sims will abandon them.  But does bad traffic lead to people abandoning Los Angeles in droves? Or New York?  Or Chicago?  Or London?  Or Paris?  No, people just sit in traffic all day.  And now your Sims can too!  Watch your transportation advisor go absolutely apoplectic as your streets turn to red, your roads turn to red, and your avenues turn to red.  And yet your city will still function, just like the major cities I listed above.  Of course, how well it functions depends on you.  So for those who like a challenge, check this one out!

And for smaller cities and towns, the NAM Tool will allow even lower capacities.  Until then, you can have quite a bit of fun with Simulator Z Classic.  Please let me know what you think of it.  ;D
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on October 26, 2009, 12:18:00 AM
Simulator Z Classic is evil, but delightfully evil because there's none of that mass abandonment that I had back in the day.

What congestion view level should it be to use classic?

I've chosen Low congestion view.  Before I unpaused, the city tile had been running with Simulator Z Ultra.

Here are the results:
Initial Conditions with Ultra:
(http://img196.imageshack.us/img196/6031/begincong.jpg)

(http://img196.imageshack.us/img196/4241/begintraf.jpg)

About 2 years in with Classic:
(http://img196.imageshack.us/img196/6610/midcong.jpg)

(http://img196.imageshack.us/img196/5517/midtraf.jpg)

After 10 years with Classic:
(http://img196.imageshack.us/img196/1700/endcong.jpg)

(http://img196.imageshack.us/img196/7871/endtraf.jpg)

(http://img196.imageshack.us/img196/8406/endvol.jpg)
Title: Re: Traffic Simulator Z Development
Post by: z on October 26, 2009, 12:29:12 AM
Simulator Z Classic is evil, but delightfully evil because there's none of that mass abandonment that I had back in the day.

Yes, that's exactly the point!  ;D

Quote
What congestion view level should it be to use classic?

That's a good question.  Technically, it should have its own, and if people like this, I'll make one for it.  In the mean time, the "Standard" data view, which was designed for the Maxis simulator, is almost perfect.  "Z_Low" is actually much too high.

And of course, you're actually referring to the volume data views, as I can also tell from your pictures.  As you can see, the congestion data view is automatically set correctly.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on October 26, 2009, 01:30:50 AM
Heh, now traffic volume view with the Standard View is much more red.  I'll be testing with Classic across my region to to how it works out in getting commuters to where I intend them to go.

For Honolulu "metro" commuters, ~10% take TheBus, 15% carpool, 7% walk, 2% bike, and the remaining ~66% drive alone.  I'm guessing, though, it's still American in terms of commuter travel type percentages.
Title: Re: Traffic Simulator Z Development
Post by: z on October 26, 2009, 02:08:49 AM
I'm guessing, though, it's still American in terms of commuter travel type percentages.

That's right.  But we wouldn't want our European friends to feel left out, would we?  So here is

Simulator Z - The Classic European Version

:D $%Grinno$% :D

Note:  This simulator is not in compliance with the Simulator Reduction Act of 2009.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on October 26, 2009, 02:30:05 AM
I will download and test the European Z simulator (non-standard) as soon as I have some time for it - this week is very loaded with RL duties so it will take a while, but I'll report my findings.

Meanwhile, if various people could contribute their views on how what is considered as fairly standard for a European-style city (from the point of view of using mass transit etc - traffic simulator-related facts), I for one would be interested to read about them. Time allowing I will put in my two cents' worth into that issue.
Title: Re: Traffic Simulator Z Development
Post by: NBAFAN on October 26, 2009, 03:33:49 PM
Where do I put Simulator Z Classic?  Do I put it in the NAM folder or the NAM\Plugins folder?  Do I have to get rid of the other Sim. Z file?
Title: Re: Traffic Simulator Z Development
Post by: z on October 26, 2009, 03:49:07 PM
You put it in the NAM folder, and move your other traffic simulator to a safe place outside your Plugins folder, in case you want to restore it.  If you want an accurate Data Volume View to go with the new simulator, you should use the "Standard" view from the NetworkAdddonMod Volume Data View (http://sc4devotion.com/csxlex/lex_filedesc.php?lotGET=1856) and move the existing Volume Data View out of the way.
Title: Re: Traffic Simulator Z Development
Post by: NBAFAN on October 26, 2009, 04:01:53 PM
Quote
If you want an accurate Data Volume View to go with the new simulator, you should use the "Standard" view from the NetworkAdddonMod Volume Data View and move the existing Volume Data View out of the way.
Is this included with the June2009 NAM?
Title: Re: Traffic Simulator Z Development
Post by: z on October 26, 2009, 04:54:37 PM
Yes, the proper Volume Data View is automatically added depending on which traffic simulator you choose.

You could also simply rerun the NAM installer and choose Simulator C (Standard), which is actually the Maxis simulator.  This will automatically get you the correct Volume Data View, and this has the advantage that it will include the new Subway and Subway Building views as well, both tuned for Simulator Z Classic.  It's actually a somewhat better approach than the one I first mentioned.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on October 27, 2009, 11:31:02 PM
Bwahahahahaha!

Sim Z Classic is PERFECT. I want traffic jams in my lovely rural towns.  ;D


By the way:

Quote
Also, if people in other parts of the world think that a different setting is needed for their region, please let me know, and please give me an idea of what seems right (i.e., 20% more buses, etc.).  We are trying to make as many choices available as possible in as simple a way as possible.

Australia is approximately halfway in between the Americans and Europeans when it comes to transit mode usage, though buses are used more commonly than rail (the next most common), cars are the most common, probably about 40-50% use cars.

I don't know yet what the usage percentages for bus/rail/etc break down into, so I'm not sure if that's basically identical to Sim Z Classic. :P
Title: Re: A new traffic simulator
Post by: jplumbley on October 28, 2009, 03:56:06 PM
ok so lets bring some of my test results to the public....

1. one interesting side effect that i've been able to reproduce over and over again is that my game and cities load twice as fast (if not faster) than before when i was using the NAM traffic simulators...curious...it was the only thing changed.

2. while commute time dropped only slightly over NAM simulator AP, traffic volume decreased, congestion decreased, and population increased. how if all my transportation volume categories decreased is my population rising?

3. my population is increasing, but the amount of abandoned buildings is increasing (all due to commute time)...weird...and commute times are decreasing from before...

4. one curious thing i noticed is that my sims take the freeway to work, but not home...ramps are exactly the same on both sides as i use the feeder road system. they all want to take avenues home from work...

5. is there a park and ride aspect that i might be missing? that seems like it should be my problem...it looks like what happened when i installed the AP simulator and hadn't placed parking garages and lots...


More results to come...

You have the park and ride version installed, you need to place parking garages for Sims to drive to before they reach their destinations.  If there is no parking lots, your Sims will walk to work instead of drive.  Many of your buildings will abandon in this case since they are walking and many of them wont walk past 10 or 12 tiles give or take.  Your population may be rising because the buildings within range of jobs will either rebuild with a higher capacity building or they will just fill up instead of being on 70-80% at capacity.  Your congestion will go away due to the Sims walking.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on October 28, 2009, 08:54:19 PM
Just a question - it seems using Z Classic had an unintended consequence: are people supposed to riot as a result of traffic?

Or is this unrelated?
Title: Re: Traffic Simulator Z Development
Post by: z on October 28, 2009, 11:00:06 PM
There's not a direct connection between rioting and traffic, although traffic can have an effect here.  Riots occur when the Mayor Rating of one or more tiles reaches -50.  (That's a minus 50.)  The Mayor Rating is affected by all sorts of things; included within these are commute time and traffic noise.  Commute time will definitely go up with Simulator Z Classic, because that's an effect of congestion.  I don't believe traffic noise is affected.  But the traffic factors by themselves are not enough to cause riots; put together, they can drop your Mayor Rating on a tile by 14 points at most.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on October 28, 2009, 11:32:00 PM
Well, my mayor rating at the time was +50, and yet I somehow got a riot happening. I have no idea how that happened...
Title: Re: Traffic Simulator Z Development
Post by: z on October 29, 2009, 12:03:47 AM
It's not your global mayor rating, it's the local mayor rating of the individual tiles, which varies greatly.  You need to check it out in the Data Views.
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 29, 2009, 06:14:55 PM
Just a question - it seems using Z Classic had an unintended consequence: are people supposed to riot as a result of traffic?

Or is this unrelated?

That's awesome!  &apls
*visions of LA and NY traffic riots danced through his head*
 :'( I can't stop laughing  :'(

Z of course answered this well, but I got such a good laugh out of this I had to say something.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on October 29, 2009, 08:51:00 PM
It's not your global mayor rating, it's the local mayor rating of the individual tiles, which varies greatly.  You need to check it out in the Data Views.


I forgot to check that particular data view - but when I re-checked it, the mayor rating was quite red in that immediate area... perhaps b/c of traffic? There was also a major fire in the area which spread like... wildfire... just recently which would've dropped the rating some. But that is interesting how people just up and riot because of a combination of factors  - it only went away when I put a police station down.
Title: Re: Traffic Simulator Z Development
Post by: z on October 30, 2009, 05:55:47 AM
This post is in response to a request by jplumbley.  It concerns the effect of the pathfinding heuristinc parameter on the game.  Briefly, this parameter determines whether or not a traffic simulator has Perfect Pathfinding, merely good pathfinding, or just plain lousy pathfinding (though you won't find a traffic simulator bearing the latter name).

When I first built Simulator Z more than a year ago, I verified experimentally that Tropod's value of .003 for Perfect Pathfinding was correct, at least to within a few percent, and I have used this value in Simulator Z ever since then.  I also found through experiments that when this value was raised above .003 by any significant amount, abandonment due to commute time occurred, even when the maximum commute time in the simulator would be effectively unlimited, and even when the Sims were able to reach jobs for which they were qualified.  This effect was quite noticeable at a value of .009, which is one of the values I tested, and which is the value that is used in Simulator A.  I have mentioned this effect occasionally, and recently jplumbley challenged me on it:

I would like you to proove this...  I have not had any problems what-so-ever with abandonment in my cities due to the PH [pathfinding heuristic] being higher than yours.  If you are so confident that the PH causes abandonment, proove it with Simulator Z and raise the value to 0.009 and show me the abandonment.

And later:

You cant make that claim publically and then hide the test in a private board.  That is not right.  You should post it for everyone to see, since you have claimed it publically you should proove it publically.

So here is the post, showing exactly the test that jplumbley requested.

I'll begin with a view of the South Side of Chicago, taken in January of the year 431, during the last years of the Roman Empire.  ???  Many of the other pictures have their dates showing, so it's easy to see the timeline here.  The city has been running Simulator Z v1.2 (Low) for several decades; this version of Simulator Z was released as a beta version in August, and will be released unchanged as the official version of Simulator Z in the next NAM release.  Meanwhile, everything in the city is quite stable, with one notable exception, which I will discuss below.  Here's a picture of the city at this point; it's slightly smaller than subsequent pictures so that I could get a more panoramic view in, as I will be referring to different parts of it later.

(http://img526.imageshack.us/img526/6883/nss0.jpg)

As you can see the city looks quite healthy; if you look closely, you can see two or three buildings that have been downgraded from their initial wealth level, but other than that, all RCI buildings are occupied at their maximum wealth level.  There are no abandoned buildings.

Now let's take the exact same version of Simulator Z and modify it the way jplumbley requested.  We raise the Pathfinding Heuristic from .003 to .009, which is the value used in Simulator A.  That is absolutely the only thing we change in the simulator.  Now we run the city for an additional 19 years.  Here is a close-up view of one part of the previous picture after that amount of time has passed:

(http://img215.imageshack.us/img215/7273/nss1.jpg)

As you can see, this picture looks quite a bit different from the previous picture.  Buildings are starting to turn dark.  Usually, when buildings turn very dark, it's because they're abandoned.  But sometimes they're merely downgraded.  So let's query them:

(http://img688.imageshack.us/img688/5044/nss2.jpg)

And:

(http://img215.imageshack.us/img215/3525/nss3.jpg)

I could go on, but I think you get the idea.  I queried them all, and altogether, there are about a dozen abandoned buildings in this picture.  You may have noticed a big new building under construction in the second picture.  The construction is a result of the abandonment; there are now jobs looking for workers to replace those who left town.  At this point, this neighborhood enters a cycle of construction and abandonment, as there is demand for workers, but the pathfinder can't find a way to get them all to work.  As you might imagine, cyclic construction and abandonment is not good for a city's health.

Now we run the city for an additional 13 years; it has now been a total of 32 years that it's been running with the degraded simulator.  This is where I was able to verify what I had recently started noticing in other experiments; other problems begin to show up from the increased Pathfinding Heuristic as well.  Specifically, the population has started to rise:

(http://img202.imageshack.us/img202/3429/nss4.jpg)

You might wonder why a rising population is a problem.  Normally, it isn't in a growing city.  But this city isn't growing.  The only new construction is that which replaces abandoned buildings in the cycle I described above.  So where's the extra population coming from?  The following graph should make it clear:

(http://img266.imageshack.us/img266/3571/nss5.jpg)

Notice the two diverging lines.  They start to diverge 17 years before now, when the degraded simulation had already been running 15 years.  The top line is the population of R-$ Sims, which is increasing rapidly.  The bottom line is the population of R-$$$ Sims, which is declining.

In other words, the high-wealth Sims are leaving town and the low-wealth Sims are moving in.  This can be done with a stable number of buildings, since RCI buildings hold far more low-wealth Sims than high-wealth Sims.  And in fact, this is exactly what's happening.  Querying a lot of high-wealth buildings that have obviously been downgraded shows that they are now filled with low-wealth Sims, unlike the first picture.

To my knowledge, this effect has not been noticed anywhere before.  People often wonder why high-wealth residential buildings won't grow in their cities, and I've seen many valid explanations advanced.  But I have never seen it mentioned that the traffic simulator may be at fault, which is clearly what's happening here.

Meanwhile, earlier in this post I mentioned that there was an exception to the general stability of this city before I switched simulators.  You can see it in the first third of the above graph, which represents the period before the switch.  Here you see the exact opposite from what you see in the last third of the graph, although the effect is not as dramatic.  The high-wealth population of the city is increasing, while the low-wealth population is decreasing.  But here, the high-wealth population is increasing faster than the low-wealth population is decreasing, which would seem to imply that new high-wealth construction is occurring.  I've witnessed some of this construction, and I've seen this effect in all my cities; it started when I switched to the v1.2 version of Simulator Z.  Why is this increase happening?  I'm not sure; perhaps someone more familiar with the demand aspect of this game would know.

Finally, let's run the simulator a final four years and take a final look around:

(http://img204.imageshack.us/img204/4020/nss6.jpg)

Here we see more abandonment, although it's impossible to say exactly when it happened.  You can see many abandoned buildings near the bottom of the picture, to the left of the high school, and another group of abandoned buildings at the upper right of the picture, near the top edge of the city.

But have things leveled off?  After 36 years, is abandonment restricted to those areas where it's already occurred, or is it still spreading?  The following picture should answer that question:

(http://img688.imageshack.us/img688/1421/nss736.jpg)

Here we see five buildings with no-job zots.  $%Grinno$%  We know what's going to happen to them.

I should also mention at this point that I have meticulously kept up city services throughout this whole period.  It's obvious that there are no power or water problems.  But I have also maintained education, health, and other services at full capacity as well.  I have taken just as good care of this city when it was running the degraded simulator as I did when it was running the standard simulator.  And overall the other data graphs show little or no change; the biggest change is the Education and Life Expectancy graphs, which are both down about a couple of percent.

Before closing, I'd like to review one of the statements I quoted from jplumbley above:

Quote
I have not had any problems what-so-ever with abandonment in my cities due to the PH [pathfinding heuristic] being higher than yours.

At first, I was willing to take this statement at face value - I certainly have no reason to doubt jplumbley's experience.  But as I reflected on the the quote, I thought, How would he know?  For that matter, how would anyone running Simulator A or B know if "Abandoned due to commute time" was due to commute time limitations, or a pathfinding heuristic that was too high?  In truth, there is no way to know.  The information just isn't there.  So players who use traffic simulators with a pathfinding heuristic greater than .003 may experience the ill effects that I've shown above without having any idea (or any way to know) that it's the pathfinding heuristic that's causing these problems.  And in the cases where that is the cause, there is nothing the players can do to make their city work better, short of rebuilding it in a different way.

Just how serious is this problem?  As you might expect, it depends on your city.  The problem has to do with the traffic simulator's ability to find complex paths, and the complexity of paths rises exponentially with the size of cities.  My experience has been that all my Chicago cities (which are all on large tiles) experience this problem to a similar extent when played with a higher pathfinding heuristic, even though they are very different in nature.  These cities are all modeled on the actual city of Chicago, using all the city's streets and built exactly to scale.  Zoning is the same as Chicago's wherever possible; in some cities (including the Near South Side), I had to put in some extra commercial zones to balance things a bit, as the game at the time I built the cities couldn't handle the large distances that people regularly commute in the real city of Chicago.

So for some large cities, such as mine, the problem can be fairly serious, as you can see above; even after 36 years, abandonment was continuing.  For other large cities, where zones are built much closer together, the problem could be expected to be less serious.  However, it's hard to predict by how much.  In the second picture in this post, the buildings that are abandoned face buildings with suitable open jobs just a few blocks away.

With medium-size tiles, the problem could be expected to be far smaller, due to its exponential nature, and it could be expected to be far smaller still for small tiles.  But much more research would be needed to quantify exactly what this means.

In the mean time, I think it is safe to answer the original question in the following way:

Using a pathfinding heuristic of .009 or higher can lead to abandonment due to commute time, and this effect can be significant in large cities.  Such values for the heuristic can also make a city far less attractive to high-wealth Sims.  These effects become more pronounced both with increasing city size and increasing values for the pathfinding heuristic.

For reference, the pathfinding heuristic used in both Simulator B and Cogeo's proposed Universal Simulator are .025; the original Maxis simulator uses .09.  Tropod's personal traffic simulator used .003, the same as all versions of Simulator Z.  Tropod called this Perfect Pathfinding, and through experiments, I have verified that it is.  But description of those experiments will have to wait for another day...
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 30, 2009, 06:39:24 AM
Before closing, I'd like to review one of the statements I quoted from jplumbley above:

At first, I was willing to take this statement at face value - I certainly have no reason to doubt jplumbley's experience.  But as I reflected on the the quote, I thought, How would he know?  For that matter, how would anyone running Simulator A or B know if "Abandoned due to commute time" was due to commute time limitations, or a pathfinding heuristic that was too high?  In truth, there is no way to know.  The information just isn't there.  So players who use traffic simulators with a pathfinding heuristic greater than .003 may experience the ill effects that I've shown above without having any idea (or any way to know) that it's the pathfinding heuristic that's causing these problems.  And in the cases where that is the cause, there is nothing the players can do to make their city work better, short of rebuilding it in a different way.

I appreciate that you posted your test.  I need some time to read it much closer though, later.

I do have a response on this quote though...  I know I do not get abandonment from the PH, because I do not get abandonment in my cities, especially not in the way you have shown in your city on this test.  The only time I start getting abandonment in my cities is when I have over-congested a section of my city, and in that case it's easy to fix by building another road, MT line, etc.

Maybe, it is just the way I play that I do not get abandonment in the way you do...  I dont know that answer.  But I do not have the same experiences you do.
Title: Re: Traffic Simulator Z Development
Post by: z on October 30, 2009, 07:18:27 AM
That sounds quite reasonable.  I know that it's certainly quite possible to use Simulator A without getting abandonment.  I think what you said in your last line sums it up - the way a person plays is a very big factor here.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on October 30, 2009, 08:15:56 AM
What would happen if the PH was reduced further? Would it start to degrade (ie, same way as increasing it to .009) or would it simply just slow the computer down even more as it tries harder to calculate a route accurately?

Quote
The only time I start getting abandonment in my cities is when I have over-congested a section of my city, and in that case it's easy to fix by building another road, MT line, etc.

The problem is that some people don't like having to add an extra road, etc because it doesn't fit into their playing style. Which makes perfect sense, really. Everybody plays differently, and as a consequence, the simulator may not always be able to cope with the circumstances that are generated.

It's possible that your city was grown and geared to the particular PH that you originally set for Z (0.003), and once that was changed, the city no longer could cope as well with being able to find a way to and from work for its individual citizens. It's also possible that the simulator you begin your city with may affect a city more than originally thought when it is changed or altered.

Cyclic construction and abandonment is never good - and I've realised how useful a tool having the dilapidation occur is... if you use the No Abandonment mod, for instance, that doesn't actually take away the building's ability to abandon, which can be a problem because you don't get the visual confirmation that there is a problem in that area of the city.
Title: Re: Traffic Simulator Z Development
Post by: SC4BOY on October 30, 2009, 11:56:03 AM
...- and I've realised how useful a tool having the dilapidation occur is... if you use the No Abandonment mod, for instance, that doesn't actually take away the building's ability to abandon, which can be a problem because you don't get the visual confirmation that there is a problem in that area of the city....

I certainly agree with this part of your statement.. I never use that mod..
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 30, 2009, 04:35:08 PM
The problem is that some people don't like having to add an extra road, etc because it doesn't fit into their playing style. Which makes perfect sense, really. Everybody plays differently, and as a consequence, the simulator may not always be able to cope with the circumstances that are generated.

It's possible that your city was grown and geared to the particular PH that you originally set for Z (0.003), and once that was changed, the city no longer could cope as well with being able to find a way to and from work for its individual citizens. It's also possible that the simulator you begin your city with may affect a city more than originally thought when it is changed or altered.

I went looking for a quote I couldn't find because I feel I have said this before in some other post.  My goal for Simulator A was not to make the "perfect" Simulator fo ALL styles of play, simply because I do not believe that there can be one Simulator that suits everybody's needs or wants out of thier style of gameplay.  Some people want to build the pretty city for their MD.  For me, and some others out there, I like the chellenge of figuring out how to re-route my Sims to make better use of my transit network.  I could care less about population or how pretty everything is, my enjoyment comes from the transit system.  My Simulator was built to tune and make that part of the game still enjoyable, not remove it.


The Simulator you play with has great implications on how you build your city from the start.  This was one thing I tried to teach when I released Simulator A....  I suggested for people starting a new City that they start with the "Hard" version for two reasons, the first being with lower capacities you will see issues with your cities sooner as they grow and second so that people realize your cities will still work with "low" capacities in them, you just have to plan a little differently and actually think about how traffic moves in your city.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on October 30, 2009, 04:43:33 PM
EDIT:  Ok, I got answers for the following post, from the other thread.

I realized something in another thread.  Referring back to my region, Sims weren't commuting to the industrial areas along the coast because they weren't the closest jobs.  Isn't the traffic simulator based on a residential building as the start point and the closest available job as the end point?  It makes sense when considering the case where commuters have jobs within the same city tile.

Neighbor connections are the closest jobs for many areas of a city tile.  If the game only considers the closest job for a commuter, why aren't "neighboring" commuters not going to the same neighbor connection?  There seems to be a bit of randomness, or some sort of determination that another "job" is closer.

For example, a ground highway neighbor connection is the closest job.  Sims that live right next to that neighbor connection are crossing over the highway and using a surface street neighbor connection instead.  There is an onramp somewhat further away, and the Sims living close to the on-ramp choose the ground highway neighbor connection.  But some of their neighbors don't, and choose the surface streets neighbor connections instead.  Also, when I have two neighbor connections side by side (to simulate a wide one-way street), the commuters choose either neighbor connection tile.



I used to have that cyclic dilapidation and construction before using Simulator Z, and I don't remember having that now.  I do have the CAM, and it's been present before I used Simulator A.

I've said the following in ldog's thread:
Quote
There are instances where there are jobs and residential demand in the same city tile, but new housing development abandons.  

The latest example I had of this is when I widened a street and had to destroy a line of residential houses.  The area is desirable, and it's quite close to available jobs.  R$ Sims came, they had the no-job zots, and then their buildings abandoned.  So, I demolished those abandoned buildings and planted trees to jumpstart the area.  Sometimes new development comes, it's successful, other times nothing wants to get built (R, C and I).  I do the unzone-rezone-tree trick and it won't develop.  That may be another problem.  But, after many years later, successful development may occur without abandonment.  The only thing in the game that I know takes years to update is the traffic simulator.
Title: Re: Traffic Simulator Z Development
Post by: z on October 30, 2009, 07:36:51 PM
What would happen if the PH was reduced further? Would it start to degrade (ie, same way as increasing it to .009) or would it simply just slow the computer down even more as it tries harder to calculate a route accurately?

I tried this when building Simulator Z, and the results were exactly as predicted by the A* algorithm.  Pathfinding accuracy did not increase at all, but CPU time rose significantly.  This is one of the factors that led me to believe that .003 was indeed the Perfect Pathfinding heuristic.

Quote
It's possible that your city was grown and geared to the particular PH that you originally set for Z (0.003), and once that was changed, the city no longer could cope as well with being able to find a way to and from work for its individual citizens. It's also possible that the simulator you begin your city with may affect a city more than originally thought when it is changed or altered.

It actually works the other way around.  When I originally built the Near South Side, I started out with a modified version of the CAM simulator, which uses a pathfinding heuristic of .0465.  The city was in much worse shape than shown in any of the pictures above.  I expanded the network capacities and then the commute times to those of the current Simulator Z.  This helped, but the city was still in a lot worse shape than shown above.  Finally, I started working with the pathfinding heuristic.  First, I dropped it to .025, which helped a lot.  Then I dropped it to .009, which helped even more, and in fact left me with a city looking very much like the one shown above for this value.  (Even the abandonment was in the same places.  And traffic jams that had existed for centuries in the area above where I first showed abandonment disappeared literally overnight.)  Then I gradually reduced the value all the way down to zero.  After .003, there was no further benefit though, and CPU times just started rising.  (With this prototype version of Simulator Z, there was still some abandonment due to commute time at .003, but it was caused by other factors, which have since been largely or completely fixed.)

Also, following the tie-breaking strategies that help A* work better, I was able to keep CPU time constant between .009 and .003.  This shift from exponential growth to constant use of the CPU was another indication that I had hit the perfect pathfinding number at .003.

So that's the story of how I arrived at .003 as being the Perfect Pathfinding heuristic.

When building the city, the changes that appeared from changing the simulator appeared quite rapidly.  However, repeating those tests by rebuilding the city from scratch would have taken a very long time.  Instead, jplumbley's suggested testing method was much faster, and ended up yielding the same results.  The tests themselves had to run longer, though, due to the way the traffic simulator works.  Once Sims have jobs, they hold onto them until something affecting their employment changes.  This means that once a city has been built with Simulator Z, you can switch to any other simulator, and the city will run just as well - for a while.  For example, I have taken the Near South Side and switched from Simulator Z to the Maxis simulator, which could never have been used to build that city.  Yet everything runs fine after I switch - for a while.  Even though the existing routes are largely in excess of what is permitted by that simulator, they persist, because the game sees no need to recalculate them.  Eventually, though, things begin to degrade, and as you would expect, they degrade much worse than in the example shown above.

So if you switch from some other simulator to Simulator Z, you will see the benefits quite quickly.  On a large tile, traffic patterns should show a major change within two years, and should be complete within eight.  On the other hand, if you move from Simulator Z to any other simulator, it will take substantially longer for the limitations of the new simulator to completely manifest in your city.

Quote
Cyclic construction and abandonment is never good - and I've realised how useful a tool having the dilapidation occur is... if you use the No Abandonment mod, for instance, that doesn't actually take away the building's ability to abandon, which can be a problem because you don't get the visual confirmation that there is a problem in that area of the city.

Agreed.  Between what is provided by Simulator Z and the CAM, I see no need for what is provided by the abandonment mod and the various demand mods, and I would recommend against them.

Neighbor connections are the closest jobs for many areas of a city tile.  If the game only considers the closest job for a commuter, why aren't "neighboring" commuters not going to the same neighbor connection?  There seems to be a bit of randomness, or some sort of determination that another "job" is closer.

There actually is some randomness in determining whether or not a Sim will cross over into a neighbor tile for a job.  More specifically, my experiments with the Simulator Z prototypes showed that the probability that a Sim will do so is related to the product of the maximum commute type and the Sim's travel type speed.  That's why the maximum commute time is set so high in Simulator Z; it's to enable effective intercity commuting down to the level of car and bus speeds.  Of course, this can cause pedestrians living near the edge of a tile to be more willing to cross into a neighbor tile as well, but the result is usually much smaller than what you observed in your cities. 
Title: Re: Traffic Simulator Z Development
Post by: ldog on October 30, 2009, 08:36:36 PM
I've got 2 new simple questions and being they are directly Z sim questions were more appropriate back here than in my thread.
Also I did not miss or discount above posts but I haven't had time to digest them so am not gonna comment(yet).

1. The clean air ordinance. A prime example of the kind of out of the box thinking that proves a lot of thought and effort went into sim Z. Now I understand why Maxis made it work the way they did. I also understand why you chose to make the modification you did. What I don't understand is why Maxis didn't make the car smogging ordinance work the way you did the clean air? And do you think it would be safe to make it work the way you did the clean air? I can explain what I mean in better detail but trying to keep it brief(er) :P

2. The traffic item (one of the other extra exemplars in Z). What exactly does it do? I mean I can see it adjusts scaling on one of the data graphs but I don't understand which or how much.

Also having been once again more closely re-reading some posts and reading some new ones besides.
Uh...wow...Steve I have seen so many instances of people being downright belligerent with you and you try to help them not once, not twice, but three times on average.
So while I "personally" didn't deserve the attitude you gave me initially, I can see how that would tend to wear on you after a year of putting up with it and I got the results of "this is what happens when people mess up things for the next guy to come along". I really cannot blame you for your initial reluctance to help me. This isn't an apology on my part by any means but...I what I am trying to say is that I have a newfound extra measure of gratitude to you for the time you have taken to answer my questions.

I hope no one here mistakes my enthusiasm for learning as trying to just start trouble or be a jerk. I know sometimes I get so into an argument (most people put a negative connotation on the word but I don't see it that way) that I forget my manners, and while I may not be getting upset, I can lose sight that the people on the other end might be.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 30, 2009, 08:38:16 PM
So if you switch from some other simulator to Simulator Z, you will see the benefits quite quickly.


I dont think this has been tested enough to claim that.  You've only tested on your city, a style where you have built the city to "scale".  It would be interesting to see how this one change in the PH effects other play styles.  There is a big question of why do I not get abandonment with a PH of .009 but you do?  Maybe there was an anomoly in your experiment?  I simply have not seen anything like that happen in my cities other then when I was using the MAXIS Default Simulator.

I am not trying to challenge your test, but I think it needs more testing.  There were numerous test of Simulator A before it was officially released and these tests were published in this thread:

http://sc4devotion.com/forums/index.php?topic=3508.60

Only one or two of them even mentioned having abandonment problems which were determined to be from congestion problems in their cities.  The one that would stand out most was the test by Nate (xxdita), he had about half of his city go abandoned due to the layout of his zones with all the residential in the corner and the jobs both Ind and Com on the opposing sides forcing all the Sims to snowball through the City before any of them reached thier destinations.  After some re-zoning, his abandonment issue was gone and his medium tile City rose from under 800k in population to over 1.8 million.  After the thread was closed, I still talked with Nate on MSN from time to time never once did he have abandonment problems after the re-zoning and his medium tile city reach an impressive 2.8 million Sims while he was testing the CAM.

There were about 8 or 10 people who provided testing results in that thread, I find it hard to discount that they did not report any abandonment problems that could not be attributed to simple congestion.
Title: Re: Traffic Simulator Z Development
Post by: z on October 31, 2009, 04:02:29 AM
What I don't understand is why Maxis didn't make the car smogging ordinance work the way you did the clean air?

The Car Smogging ordinance is a strange bird indeed.  Its effect on the various types of air pollution is identical in every way to the unmodified Clean Air Act.  Your question is one of the first ones that came to me when I looked at its insides.  I don't know the answer.

Quote
And do you think it would be safe to make it work the way you did the clean air?

It would certainly be safe.  The reason I chose the Clean Air Act is that the property that I modified affects all vehicle pollution, not just cars.  So I saw it as essentially an omission from the Clean Air Act.  The Car Smogging ordinance just seemed to me to be a mistake that was better left alone.

Quote
The traffic item (one of the other extra exemplars in Z). What exactly does it do? I mean I can see it adjusts scaling on one of the data graphs but I don't understand which or how much.

It scales the Commute Time Graph to be about as accurate as it can be (which is not very accurate).  See this post (http://sc4devotion.com/forums/index.php?topic=5382.msg189449#msg189449) for the gory details.

I dont think this has been tested enough to claim that.  You've only tested on your city, a style where you have built the city to "scale".

I also tested this on my New York cities, which were not built to scale, were built on medium and large tiles, and were originally built in a completely different style, as they were the first cities I built in SC4.  My conclusions were also based on the feedback of my testers, and later from users.

Since I so often refer to "feedback from users," "quotes from users throughout the threads," etc., and since these would take a lot of work for any individual to find, rather than have everyone who is interested do all that work, I will put these all together in a single post.  They will be numbered, and linked back to their original post.  That way, it will be much easier to cite the data behind many of my conclusions, and much easier for people to verify it.

Quote
There is a big question of why do I not get abandonment with a PH of .009 but you do?

That's actually very easy to explain.  As you have correctly stated previously, Simulator A allows a Sim to drive across an entire large tile during a commute period.  This means that on a medium tile, a Sim can drive from any point to any point during a commute period, as long as there is not excessive congestion.  So for most medium tiles, there should never be any abandonment due to commute time caused by exceeding the maximum commute time.

As for the pathfinding heuristic, I described how the complexity of paths varies exponentially with the size of a tile, which means that it declines exponentially when going from a large tile to a medium tile.  As the complexity of paths declines, the need for perfect pathfinding declines, and a value of .009 is sufficient for a much larger percentage of cases.  (But not all, as I will soon show.)  And if you build with your zones close together, you reduce the path complexity further, making it even more unlikely that a value of .009 will give you trouble.

Quote
  Maybe there was an anomoly in your experiment?

I don't think so, especially since I ran two types of experiments (forwards and backwards) a year apart, and I also ran experiments in different cities with different styles, and still got identical results.  Also, I am able to explain both my results and yours without contradiction.  Instead, I think that this effect appears much more often than people realize, and has simply gone unrecognized until now.  For example:

Quote
There were numerous test of Simulator A before it was officially released and these tests were published in this thread:

http://sc4devotion.com/forums/index.php?topic=3508.60 (http://sc4devotion.com/forums/index.php?topic=3508.60)

Only one or two of them even mentioned having abandonment problems which were determined to be from congestion problems in their cities.  The one that would stand out most was the test by Nate (xxdita), he had about half of his city go abandoned due to the layout of his zones with all the residential in the corner and the jobs both Ind and Com on the opposing sides forcing all the Sims to snowball through the City before any of them reached thier destinations.

This is just the type of example I was looking for.  First, let's look at Nate's introductory comment:

Quote
Suddenly, I'm facing abandonment & my traffic network just isn't able to deal with the higher stages of CAM. Can't get anything above a stage 13 to grow, even with ample Regional Capacities, and all other caps met. Played for 20 years, and routes changed consistently.

The last sentence is what's most significant - the routes changing consistently.  Why should they do that if the pathfinding is correct?  For that matter, why should he get any abandonment at all?  The one thing that could cause Sims to run past the maximum commute time on a medium tile running Simulator A is excessive congestion.  Fortunately, Nate posted his congestion map:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot214.jpg)

That doesn't look too bad.  If you think that the congestion on the diagonal is a problem, remember that there are no true diagonals, and that any combination of orthogonal routes is just as efficient.  In fact, the congestion on the diagonal and the uneven congestion elsewhere is in itself evidence that the pathfinding heuristic is set too high.  If you look at all the examples of Simulator Z, you see that congestion is spread out evenly to minimize travel times.  And it's Perfect Pathfinding that allows that even spreading.

If you don't accept this explanation, how do you explain the abandonment?  There's enough commute time and enough network capacity; the pathfinder simply isn't finding workable routes.  That's purely a function of the pathfinding heuristic.  Your solution was to have Nate move his zones closer together.  That fixed his problem because it simplified the paths.  A value of .009 was now sufficient for workable paths to be found.

I remember when this all happened, and Nate really became a convert to your simulator after this.  There was one post that particularly stuck in my mind.  One user was complaining that his city used to work, but now with Simulator A, he was getting abandonment.  Nate's reply was that this person had to be better at zoning, and as good mayors, we should be up to the challenge.

In other words, we were supposed to change our cities to fit the simulator.

This was the first time I began to question what was happening with Simulators A and B.  It seemed to me that the traffic simulator should be designed for the city, not the other way around.  So this is when I began work on what eventually became Simulator Z.

Quote
After the thread was closed, I still talked with Nate on MSN from time to time never once did he have abandonment problems after the re-zoning and his medium tile city reach an impressive 2.8 million Sims while he was testing the CAM.

This is not surprising.  If you build cities that are designed to work well with Simulator A, then they will work well with Simulator A.

Quote
There were about 8 or 10 people who provided testing results in that thread, I find it hard to discount that they did not report any abandonment problems that could not be attributed to simple congestion.

As I have tried to show, some abandonment problems, such as Nate's, were caused by pathfinder inefficiency, but were not recognized as such.  I see no evidence in that thread that such a possibility was even considered, much less tested.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on October 31, 2009, 11:47:47 AM
This is just the type of example I was looking for.  First, let's look at Nate's introductory comment:

The last sentence is what's most significant - the routes changing consistently.  Why should they do that if the pathfinding is correct?  For that matter, why should he get any abandonment at all?  The one thing that could cause Sims to run past the maximum commute time on a medium tile running Simulator A is excessive congestion.  Fortunately, Nate posted his congestion map:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot214.jpg)

That doesn't look too bad.  If you think that the congestion on the diagonal is a problem, remember that there are no true diagonals, and that any combination of orthogonal routes is just as efficient.  In fact, the congestion on the diagonal and the uneven congestion elsewhere is in itself evidence that the pathfinding heuristic is set too high.  If you look at all the examples of Simulator Z, you see that congestion is spread out evenly to minimize travel times.  And it's Perfect Pathfinding that allows that even spreading.

If you don't accept this explanation, how do you explain the abandonment?  There's enough commute time and enough network capacity; the pathfinder simply isn't finding workable routes.  That's purely a function of the pathfinding heuristic.  Your solution was to have Nate move his zones closer together.  That fixed his problem because it simplified the paths.  A value of .009 was now sufficient for workable paths to be found.

Do you remember that Congestion Data View mod I made that didn't really work as well as I thought it did....  Guess what, it was used in that experiment.

The problem was congestion, you can tell by the quarter circle of red routes that are shown around the Residential area.  And the fact that the problem was fixed simply by re-zoning and spreading out the Sims through the jobs.  Like I said, Nate has not complained about abandonment problems since, and in fact after talking to him yesterday still uses Simulator A with medium tile cities in the millions for population.  If he hasn't reported abandonment problems in the 2 years he has been using Simulator A, then maybe there is something else that is effecting the way the PH works.

You agree that when you change one value in the Simulator that you will need to change a number of other things as well...  Maybe something you have changed in your Simulator Z that is different from Simulator A has made it so that the PH is more sensitive to these changes than it is in Simulator A.  It just does not make sense that I amoungst many others do not experience the same abandonment problem you do, unless there is something you have changed with Simulator Z that makes it more sensitive to the changes in PH.

Quote
I remember when this all happened, and Nate really became a convert to your simulator after this.  There was one post that particularly stuck in my mind.  One user was complaining that his city used to work, but now with Simulator A, he was getting abandonment.  Nate's reply was that this person had to be better at zoning, and as good mayors, we should be up to the challenge.

In other words, we were supposed to change our cities to fit the simulator.

This was the first time I began to question what was happening with Simulators A and B.  It seemed to me that the traffic simulator should be designed for the city, not the other way around.  So this is when I began work on what eventually became Simulator Z.

This is not surprising.  If you build cities that are designed to work well with Simulator A, then they will work well with Simulator A.

Let me ask you, what happens in the real world?

Does traffic flow in the way "WE" tell it to?
No, it doesnt...  We provide a number of routes for the population to use, but ultimately it is thier choice how they drive to work.

Can we change a factor in the "Simulator" of life that will make it all better?
Of course we cant...  There is no Simulator to modify to make our cities work.  They will just keep getting more and more congested.

What did they have to do in Boston when thier highway was over-crowded causing 10-hour a day traffic jams?
Boston had to re-build thier highway underground in a project called the Big Dig, because they did not have the option to expand the old one.

What is the trend in Europe in regards to zoning?
Due to the space requirements in Europe, they are forced to bring residents and work closer together not only for the reason of limited space but because it reduces overall traffic in the cities.

What is happening in the downtown cores around the world which used to be reserved for commercial towers?
At least in Toronto anyways and I am sure in other parts of the world, there are more and more condos (residential units) being built right in the middle of the downtown core.  The initiative is there for the population to live closer to work instead of commute from the "bedroom" communities so that we can reduce traffic, promote walking or MT usage.

So, do I think Simulator A has addressed real life situations and kept them part of the game?
Most definitely and there is no way you are going to convince me otherwise.  Simulator A is NOT a Sandbox Simulator like Simulator Z and it never will be.

I think you need to accept the fact that our goals are different and finally admit that Simulator A has done what was intended and works fine for what it was intended to do.  At the same time you need to stop bad mouthing Simulator A and putting it down for simply being a more challenging Simulator than Simulator Z.

Quote
As I have tried to show, some abandonment problems, such as Nate's, were caused by pathfinder inefficiency, but were not recognized as such.  I see no evidence in that thread that such a possibility was even considered, much less tested.

The users were asked to report abandonment.  If they did not report it, then where was the inefficiency?  Nate and SC4BOY were the only ones, SC4BOY was because he had 1000s of Sims trying to use 1 street to enter his CBD.  Nate was because he need to re-zone.
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 01, 2009, 12:47:15 AM

This is just the type of example I was looking for.  First, let's look at Nate's introductory comment:

The last sentence is what's most significant - the routes changing consistently.  Why should they do that if the pathfinding is correct?  For that matter, why should he get any abandonment at all?  The one thing that could cause Sims to run past the maximum commute time on a medium tile running Simulator A is excessive congestion.

As I said in the testing, play was for 20 years before my initial report. I don't think it was so much as the PH not working as it was the city & the game itself adjusting to the new traffic simulator. Which was a fairly significant adjustment...

Quote
Fortunately, Nate posted his congestion map:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot214.jpg)

That doesn't look too bad.  If you think that the congestion on the diagonal is a problem, remember that there are no true diagonals, and that any combination of orthogonal routes is just as efficient.  In fact, the congestion on the diagonal and the uneven congestion elsewhere is in itself evidence that the pathfinding heuristic is set too high.  If you look at all the examples of Simulator Z, you see that congestion is spread out evenly to minimize travel times.  And it's Perfect Pathfinding that allows that even spreading.

Even more fortunately, I also posted all of my congestion views. The only diagonals used in the city are inmy subway system. So Simulator A worked like a charm, increasing the usage of the mass transit.


Quote
If you don't accept this explanation, how do you explain the abandonment?  There's enough commute time and enough network capacity; the pathfinder simply isn't finding workable routes.  That's purely a function of the pathfinding heuristic.  Your solution was to have Nate move his zones closer together.  That fixed his problem because it simplified the paths.  A value of .009 was now sufficient for workable paths to be found.

First, let's take a look at the city in question.

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot220.jpg)

That was my playing style at the time, and it worked for me then. It really shouldn't have, and I doubt that it would have in the vanilla version of the game. For a small city, sure. But not a medium tile. I've never claimed to be any good at actually playing the game, but I've improved a bit, thankfully.

Quote
I remember when this all happened, and Nate really became a convert to your simulator after this.  There was one post that particularly stuck in my mind.  One user was complaining that his city used to work, but now with Simulator A, he was getting abandonment.  Nate's reply was that this person had to be better at zoning, and as good mayors, we should be up to the challenge.

In other words, we were supposed to change our cities to fit the simulator.

But our playing styles had already adapted to the traffic simulators previously available, however inept they've been since proven to be. Out of all currently or previously publicly available traffic sims, I would still recommend A at least 9 times out of 10. Not because I consider Jason a friend, which I do, but because it has worked the best, for me, with the least amount of problems. But no publically available traffic sim suits my personal needs when it comes to large city tiles, which is why I've designed and use my own, based on Simulator A Easy.

Quote
This was the first time I began to question what was happening with Simulators A and B.  It seemed to me that the traffic simulator should be designed for the city, not the other way around.  So this is when I began work on what eventually became Simulator Z.

This is not surprising.  If you build cities that are designed to work well with Simulator A, then they will work well with Simulator A.

As I have tried to show, some abandonment problems, such as Nate's, were caused by pathfinder inefficiency, but were not recognized as such.  I see no evidence in that thread that such a possibility was even considered, much less tested.

Notice that in the test city, my transportation system consisted of streets, roads, and avenues, mixed with buses & subways. The abandonment occured because this system was inadequate. Though it had worked quite well with the previous traffic sim I had used, which I should point out was one that was included with CAM (the easiest one, with promote biking). So adding in a new traffic sim completely changed the network capacities, and all that jazz. No longer could my Sims get to work very effectively. Also, the buildings that were upgrading, fairly quickly, closer to the jobs, caused an even more instense traffic nightmare for the Sims that lived farther away from work.
Not only was my style of playing in grids no longer acceptable, I had to seriously improve my mass transit system, going from:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot219.jpg)

To:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot236.jpg)

But I had played like an idiot because the traffic simulator I had used allowed me to do so. And now I've learned how to actually play the game, based on what I want my city to look like as it grows, and what it will take to make that happen. Granted there have been other factors that have helped as well, like a much better overall understanding of the game mechanics as a whole.
Oh, and cheating. (http://i91.photobucket.com/albums/k301/ditareinvented/YoYo%20and%20CiCi/t171210251_20186_3.gif)
Title: Re: Traffic Simulator Z Development
Post by: z on November 01, 2009, 04:22:43 AM
Do you remember that Congestion Data View mod I made that didn't really work as well as I thought it did....  Guess what, it was used in that experiment.

Oops.  Well, I guess that makes that graph pretty worthless, then.  And the conclusions I drew from it can't be supported without additional data.  And the volume data graphs are the standard Maxis ones, which top out at a volume of 1200, so no congestion information can be gleaned from them.

However, I have designed some new experiments to address your questions.  They take a long time to run, so the final results won't be ready for a while.  But the preliminary results already show some rather interesting things.  I will address  your other comments at that time.

I would still recommend A at least 9 times out of 10. Not because I consider Jason a friend, which I do, but because it has worked the best, for me, with the least amount of problems. But no publically available traffic sim suits my personal needs when it comes to large city tiles, which is why I've designed and use my own, based on Simulator A Easy.

I appreciate your contributing here, Nate, especially as I consider this a real opportunity to talk to a very skilled player who is quite enthusiastic about Simulator A.  This most recent discussion started out with some tests trying to determine what the differences between Simulators A and Z actually are in a quantifiable way.  The general subject of this thread is the development of Simulator Z, as I'm always looking for ways to improve it.  I'd like to ask you a few questions here, basically for research purposes.  You are obviously quite happy with your current simulator, and I assure you that I am not here to debate you on any points.  But I think that knowing what a player such as yourself looks for and likes in a simulator could be very useful information for further simulator development, especially since you have gone to the trouble to design your own simulator.  So if you wouldn't mind answering the following questions, I would be very grateful.  And this is a one-time request; I do not intend to turn this into a discussion.

You've obviously used other traffic simulators.  Could you please list which ones (and the capacity levels, where appropriate it?)

If the above list contains the Low version of Simulator Z, what didn't you like about it?  (Again, there will be no response from me.   $%Grinno$%)

What do you see as the biggest strength(s) of Simulator A?

What are the problems with other simulators that you referred to?

Were you ever able to build large cities (1 million Sims or more) on large tiles with Simulator A that had no abandonment due to commute time?

Which factors led you to design your own simulator, and what does it do?

Would you be willing to attach a copy of your simulator to your reply?  I always like looking at other simulators...  ;D

Quote
As I said in the testing, play was for 20 years before my initial report. I don't think it was so much as the PH not working as it was the city & the game itself adjusting to the new traffic simulator.

The new tests I am currently running have been designed to separate out many of these factors.  It appears that the PH is involved a lot more than anyone thought, including me.  Part of the reason that this has been missed is that the PH affects congestion, which of course affects commute time.  So the utlimate effect may be that the Sims do exceed their maximum commute time, but the original cause of all this may be that the PH is too high.

There's not enough data at this point from your old city to say how much of a part the PH played.  (Unless you've still got the old CAM version around, which I realize is pretty unlikely.)  However, the experiments I'll be displaying in the next day or so should give a good idea of how this functions in general.

Thanks for taking the time to read this, and thanks for whatever input you can give.
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 01, 2009, 08:56:51 AM
Ok, what I don't really get is how in Z you could ever not be able to find a valid route.
Valid route defined as "A there and back route you can complete without running out of time"

Even if we had to go the full diagonal across a large tile and back with your max commute time of 60...
1024/60=17

So as long as we can do at least 17 kph on average we can make it.
At maximum congestion all trains are still much faster, so is the highway.
Driving on roads, ave, owr at 30% speed we come up with 15, also your walking speed.
Since 1024 is absolute longest distance most of the time it is of course going to be much less, even if we have to drive out of our way to catch a train or go around a lake, mountain, etc.

So pretty much no matter what we should be able to find a valid route.

Has to be something outside the traffic simulator.
Title: Re: Traffic Simulator Z Development
Post by: SC4BOY on November 01, 2009, 09:30:01 AM
Don't forget the "across the border" commuters .. and especially if your network design allows "commuter loops" you can have HUGE commute times
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 01, 2009, 09:47:22 AM
Don't forget the "across the border" commuters .. and especially if your network design allows "commuter loops" you can have HUGE commute times

I didn't but once they are in the tile don't they follow the same rules as trips that originate inside the tile?
Title: Re: Traffic Simulator Z Development
Post by: z on November 01, 2009, 01:10:42 PM
Ok, what I don't really get is how in Z you could ever not be able to find a valid route.
Valid route defined as "A there and back route you can complete without running out of time"

In Simulator Z v1.2, about the only way you can't find a valid route is if there is none - e.g., there aren't enough jobs for your particular wealth level of Sim.  This concerns commuting within a single city.  Between multiple cities, it should still work this way; Sims have been observed commuting across four large city tiles in Simulator Z.  But for a more definitive answer, I (or someone else) will have to do a lot more testing; my current region doesn't qualify, because it was built with CAM when there was no known solution to the CAM demand bug.  I would have to build a whole new region, which I hope to do someday, but which will take months on my schedule (assuming I am doing no development work or posting).

There are other factors in the traffic simulator besides maximum commute time and the pathfinding heuristic that can prevent you from finding a valid route, even when one exists.  From my experience, I think I have fixed them all in v1.2, but it will be a while before I can say that for sure.

For those who question how realistic this commute model is, I will be addressing this issue (complete with documentation) in the post where I publish my latest test results (which are turning more and more interesting).

Don't forget the "across the border" commuters .. and especially if your network design allows "commuter loops" you can have HUGE commute times

I didn't but once they are in the tile don't they follow the same rules as trips that originate inside the tile?

Since commute time is reset whenever a Sim crosses a tile border, these commuters don't form a special case as far as commute time is concerned.
Title: Re: Traffic Simulator Z Development
Post by: SC4BOY on November 01, 2009, 03:47:50 PM
Since commute time is reset whenever a Sim crosses a tile border, these commuters don't form a special case as far as commute time is concerned.

I speculated on this.. so when a commuter is "thrown over the border" he is automatically judged to  have "found a job"?
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 01, 2009, 04:06:47 PM
Hey stupid question.
Z 1.2 is what is in the current NAM download right?
Title: Re: Traffic Simulator Z Development
Post by: z on November 01, 2009, 05:06:27 PM
I speculated on this.. so when a commuter is "thrown over the border" he is automatically judged to  have "found a job"?

Correct.

Hey stupid question.
Z 1.2 is what is in the current NAM download right?

Not a stupid question at all, especially since the answer is "no."  It will be in the next NAM release.  However, it's such a big improvement over the previous version that I'm recommending it to all Simulator Z users; you can get it here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=6122).
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 02, 2009, 02:40:45 AM
I appreciate your contributing here, Nate, especially as I consider this a real opportunity to talk to a very skilled player who is quite enthusiastic about Simulator A.  This most recent discussion started out with some tests trying to determine what the differences between Simulators A and Z actually are in a quantifiable way.  The general subject of this thread is the development of Simulator Z, as I'm always looking for ways to improve it.  I'd like to ask you a few questions here, basically for research purposes.  You are obviously quite happy with your current simulator, and I assure you that I am not here to debate you on any points.  But I think that knowing what a player such as yourself looks for and likes in a simulator could be very useful information for further simulator development, especially since you have gone to the trouble to design your own simulator.  So if you wouldn't mind answering the following questions, I would be very grateful.  And this is a one-time request; I do not intend to turn this into a discussion.

You've obviously used other traffic simulators.  Could you please list which ones (and the capacity levels, where appropriate it?)

If the above list contains the Low version of Simulator Z, what didn't you like about it?  (Again, there will be no response from me.   $%Grinno$%)

All the simulators I've used since joining Simtropolis in 2003? (http://i91.photobucket.com/albums/k301/ditareinvented/YoYo%20and%20CiCi/yociexpress07.gif)
I'm quite sure I've used all of them at one point or another. Better pathfinding, perfect pathfinding... once I found CAM, I tended to use Promote Cycling. Most of the time I played using the sim allowing for the highest capacities. Since Simulator A's release, though I continued testing newer sims, nothing's panned out for me. Sorry, I can't give you specifics on your own sim, but I just don't remember the details. i'll probably be looking into it again soon though.

Quote
What do you see as the biggest strength(s) of Simulator A?

It's more balanced, for a fairly realistic style of gameplay. Jason took the traffic sim back to Vanilla and started from scratch, using more of an evidence-based practice to decide which changes needed to be made, one at a time, and to what extent.

Quote
What are the problems with other simulators that you referred to?

Too many commuters leaving town, speeds/capacities too high or low... Have you looked at or tried to use the traffic sims that came with the CAM installer? You'll see what I mean.

Quote
Were you ever able to build large cities (1 million Sims or more) on large tiles with Simulator A that had no abandonment due to commute time?

99% of what I build are large Metropolis cities. A large tile with only 1 million people on it means I'm probably less than 20 years into the city. I have medium tiles at 3,850,000 Sims. The most populated large tile I have played lately is closer to 12 million right now.
I'd have to say that the only times I've experienced any serious abandonment issues has been when going back into a city that was started using an older traffic sim.

Quote
Which factors led you to design your own simulator, and what does it do?

I've been tinkering around with traffic sims since I learned how to use Reader.

The reasons for this specific traffic sim being developed all had to do with my style of play, and figuring out what kind of traffic sim will be needed for at least one version of CAM 2.0. I generally only use it for large tiles, though I've tested it on medium tiles with fairly good results. It can lead to more commuters leaving town than I like, especially in a city's early growth.
The first changes were to the capacities of the networks I actually use. Once I figured out how to use the Street Addon Mod, it frustrated me when all the work I had done would be pointless as soon as an upper stage building was grown. Now, it's not necessary to upgrade. I've also upped the capacity of avenues and subways, which serve as the primary arteries
 of my cities.
I've adjusted some speeds a little here & there...
walking is 7, and subways 220. (Major emphasis on mass transit)


Of course I've also had to remod some subway & bus stations to take full advantage of the new capacities.

New Capacities:
10800,13500.10800,10800,0,0,32000,13500,13500,10800,10800,10800

Simulator A Easy Capacities:
5600.13500,10800,2250,0,0,5600,13500,13500,13500,5600,10800,10800

Quote
Would you be willing to attach a copy of your simulator to your reply?  I always like looking at other simulators...  ;D

It's still a work in progress, designed for use with another work in progress (CAM 2.0), as well a mod I've been working on, and not intended for distribution... but I don't have a problem with that.

Quote
The new tests I am currently running have been designed to separate out many of these factors.  It appears that the PH is involved a lot more than anyone thought, including me.  Part of the reason that this has been missed is that the PH affects congestion, which of course affects commute time.  So the utlimate effect may be that the Sims do exceed their maximum commute time, but the original cause of all this may be that the PH is too high.

There's not enough data at this point from your old city to say how much of a part the PH played.  (Unless you've still got the old CAM version around, which I realize is pretty unlikely.)  However, the experiments I'll be displaying in the next day or so should give a good idea of how this functions in general.

Thanks for taking the time to read this, and thanks for whatever input you can give.

Not a problem. Truth be told, had I not been invited to join BSC, I probably would've ended up being a gearhead like you guys... (http://i91.photobucket.com/albums/k301/ditareinvented/YoYo%20and%20CiCi/thmonkey-9.gif)

Remind me to thank  Barby & Tage for the intervention.

- Edit... forgot to attatch the file...
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 02, 2009, 04:00:37 AM
Remind me to thank  Barby & Tage for the intervention.

Thank you for joining!
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 03, 2009, 06:33:51 PM
D'oh!
Lot of files in there Steve.
Is there a breakdown of what's what somewhere?
Title: Re: Traffic Simulator Z Development
Post by: z on November 03, 2009, 07:27:03 PM
Well, you've got your four capacities, which are documented in the NAM, plus two variations.  Files with "_ZP_" in their names are Park & Ride - I don't think you want that.  And files with "BTM" in their name are for the Bullet Train Mod.
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 04, 2009, 08:25:19 PM
Well, you've got your four capacities, which are documented in the NAM, plus two variations.  Files with "_ZP_" in their names are Park & Ride - I don't think you want that.  And files with "BTM" in their name are for the Bullet Train Mod.

LOL, yeah I couldn't for the life of me figure out what BTM meant. I was guessing the ZP was park&ride, but I wasn't sure.
I actually am interested in the p&r, I haven't bothered to mention it in discussion because I've got enough on my plate at the moment (and then some) but I find the concept quite intriguing.

Of course now I have to go look at Nate's traffic sim too, so much to do, so much to see. :D

And thanks Nate and Tage for making me go blind :P
Title: Re: Traffic Simulator Z Development
Post by: pierreh on November 05, 2009, 02:19:10 PM
Meanwhile... over a week ago the Z Euro Simulator was presented, and we were asked to check in particular the bus usage.

I ran a comparative test with the Z Euro High and the Z Standard High, on the same city. At the start of the test the population of the city is a bit over 214k sims; this is an unfinished city in the sense that there is still plenty of room to expand it, however what there is of it is fully functional. Originally public transportation was essentially bus, with a bit of railroad (playing a relatively minor role). Recently I started to implement a GLR network in the city. Both tests were run for the same duration, 6 years and 4 months - this is because the first test had to be stopped after that much game time. It may be not enough to verify the effect of applying the Euro simulator. Aside from building two additional medical centers because the nurses gave me a hard time, I did not interfere with the city during the tests.

Here are, one below the other, some pictures of the 'standard' test and the 'euro' test:

Travel Time graph

(http://img8.hostingpics.net/pics/605034Mayere_Trajets_Std.jpg) (http://www.hostingpics.net/viewer.php?id=605034Mayere_Trajets_Std.jpg)

(http://img8.hostingpics.net/pics/459591Mayere_Trajets_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=459591Mayere_Trajets_Euro.jpg)

Bus volume

(http://img8.hostingpics.net/pics/857327Mayere_Bus_Std.jpg) (http://www.hostingpics.net/viewer.php?id=857327Mayere_Bus_Std.jpg)

(http://img8.hostingpics.net/pics/693757Mayere_Bus_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=693757Mayere_Bus_Euro.jpg)

GLR volume

(http://img8.hostingpics.net/pics/654838Mayere_Trams_Std.jpg) (http://www.hostingpics.net/viewer.php?id=654838Mayere_Trams_Std.jpg)

(http://img8.hostingpics.net/pics/700250Mayere_Trams_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=700250Mayere_Trams_Euro.jpg)

Bus, GLR and passenger train density

(http://img8.hostingpics.net/pics/602254Mayere_Densite_Std.jpg) (http://www.hostingpics.net/viewer.php?id=602254Mayere_Densite_Std.jpg)

(http://img8.hostingpics.net/pics/88055Mayere_Densite_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=88055Mayere_Densite_Euro.jpg)

The most visible difference seems to be that of the travel time – to the extent where the graph can be trusted. Travel time with the Euro Simulator is somewhat less than with the Standard one. Otherwise, the pictures and graphs are quite similar. At the end of the tests, the values for the bus and GLR densities are identical with both Simulators.

The volumes may not be sufficient to show significant differences in bus usage (and in GLR usage). I have another larger city with a subway network and buses, on which I could run the same series of tests – if possible for a minimum of 10 years (even though it is boring to just watch the calendar run, without any intervention).
Title: Re: Traffic Simulator Z Development
Post by: z on November 05, 2009, 03:16:09 PM
Thanks for the testing, Douzerouge!  This is the first feedback I've received on this simulator.  The results were quite surprising.  I had expected a fair increase in bus usage, or at least some, but there really was none at all in your tests.  This could partially be due to the layout of your city and the way your subway lines run, but there should still be a noticeable increase.  And your city size is certainly big enough.  The only explanation I can think of is that the average length of a bus trip in your city is small enough so that the changes I made (which I just verified) weren't sufficient to make an impact on bus usage.

The most visible difference seems to be that of the travel time – to the extent where the graph can be trusted. Travel time with the Euro Simulator is somewhat less than with the Standard one.

What the graph says makes sense, although it's not terribly accurate.  Bus speeds have been increased, so the Sims who take buses have shorter commutes.  Yet this wasn't enough to cause more Sims to take buses.  But the shorter bus commutes should have an impact on average commute time, and it appears that they did.  This would seem to say that we're on the right track; the speeds just need to be raised a bit more.  This whole process is nonlinear; there's a point where the speeds become high enough for the average trip that there's a large movement to buses.  We may not be far from that point; we'll see.

Quote
The volumes may not be sufficient to show significant differences in bus usage (and in GLR usage).

They should be - I don't think another test is needed.  The fact that there is no increase at all in your Traffic Volume Graph says that the changes I made were insufficient, even though they might show up somewhat more on larger cities.  So I've made another version of the Euro simulators, with significantly bigger changes.  I'd appreciate it if people would try these out, and report back their findings.  These new simulators should definitely make a difference - if anything, I may have overshot a bit.  Only testing will tell.

Douzerouge, your pictures were very helpful.  The only request I have concerns your Traffic Volume Graph.  Next time, could you please include cars as well?  Thanks!
Title: Re: Traffic Simulator Z Development
Post by: pierreh on November 06, 2009, 12:32:44 AM
I will use the latest version of the Euro Simulator from your last post, in the other, larger, city I was mentioning last night, and do another comparative test. This will however be delayed because of many RL activities - not a few of which, incidentally, have to do with public transportation issues.
Title: Re: Traffic Simulator Z Development
Post by: schack on November 06, 2009, 06:45:52 AM
Hello

I'm for some reason having troubles with Traffic Simulator Z, both v1.1 in the NAM install and the v1.2 beta3. For both of them I've used Ultra until I know how it works.
Now, the problem is quite simply that people forget where they work. I have my city split in a city (well, town for now) in the south east corner with residential and commercial areas and the industry (dirty and manufacturing) is located by a river on the west side of the map as illustrated here:
(http://img193.imageshack.us/img193/7396/citytinninghattan10kani.th.png) (http://img193.imageshack.us/i/citytinninghattan10kani.png/)
The pink circles are tunnel entrances.

For starters there was a nice rural highway between the areas and about a thousand people were commuting without issues. Then after adding some commerce in the centre of the city, some people went to work there and the rest just forgot they had a job at the industrial site and complained about a lack of jobs. So I built the northern most RHW to the industrial area and all was well in tiny town again. Now 2k people commuted via this road and things were looking bright. Adding a bit more commercial zones in the centre of town and the same thing repeated. Some people go to work there, the rest forget they work at the industrial site.
From 2k to 0 flat in a matter of months.

I've had this issue in previous cities as well and it seems pretty consistent. If I make a residential neighbourhood some way away where they aren't likely to get within easy reach of commercial development they'll stick to working at the industry, but it seems to reset every time they get close to commercial zones and I'm completely lost as to why. I like the concept of Sim Z a lot because it allows me to play with split neighbourhoods and if there is a job, they will find it.
But alas, while having some 4.5k jobs at the industry and people not filling them leaves me quite perplexed because this shouldn't happen. Even less so as they seem to just abandon their jobs and then whine to the mayor.

I hope someone has a clue as to what on earth is going on.

Edit:
To be on the safe side, since I'd already sent my complete plugin package to a friend so he could get an easy start on the game, I decided to also send him my region and have him run it for 10 years, just in case it may be my aging laptop being the culprit. Alas it wasn't.
I should add, that seeing as 99.9% of people seem to run Sim Z just fine, I don't exactly think it has to do with it, but perhaps something interacting with it in weird ways, and I reckon people reading this thread are generally the most knowledgable and can hopefully aid.
Also, after the original post, I decided to add another residential area smack bang in between my town centre and the industrial area, connected solely to the RHW4 running between the two latter. As expected and hoped, most of the workforce picked up a job at the industrial area. Oddly enough, about 15% couldn't find a job while their neighbour connected to the same stretch of street could. Not entirely sure what went wrong there. A total of 1009 people commuted to the industrial area.
Sadly as expected as well, after adding 3 commercial buildings in the town centre, 2 (two!) people from the new neighbourhood got a job in town, which meant that over the next 6 months, the remaining 1007 people slowly decided to not bother with the trip to the industrial area, instead opting to sit at home in front of the telly, voicing their discontent at the mayor.
I'm really really at a loss as to why this is happening.

Edit 2:
Things are getting absurd now. I severed the connection to my western most neighbourhood and the town centre completely so they could only go to the industrial area, and they duly did. All 2.3k of them. That meant the other neighbourhoods could start working in the city centre, and they quickly occupied all 3k commercial jobs there. I let it run for a few years at max speed and things seemed ok. Then I reattached the western most neighbourhood and immediately (!) they simply kicked out all the others from the commercial jobs in the city centre and moved in, giving up their industrial jobs and leaving the rest of the population jobless and too lazy to go to the industrial area. That really is absurd.
But after running some clean tests on a new map with very few plugins, increasingly adding plugins, I just couldn't reproduce it (despite it affecting my last 3 maps). I start doubting I'll ever figure out what's causing it.
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 06, 2009, 02:48:24 PM
Out of curiosity...
I know it's generally assumed (by me as well) that the starting trip costs only changing walking and car will have any effect, because as stated (I think by Mott as usual) "those are the only 2 types generated by residential".
I'm wondering if anyone actually tried messing with them?
If the engine actually applied them when it started calculating that leg of the trip that involved said MT, then we could bias one form of MT over another.
Title: Re: Traffic Simulator Z Development
Post by: z on November 06, 2009, 03:10:51 PM
@Schack:  Have you tried Simulator Z v1.2, available here (http://sc4devotion.com/forums/index.php?action=dlattach;topic=5382.0;attach=6122)?  It's not in the current NAM, although it will be in the next one.  It offers various improvements in general, but it has also fixed problems for a few people that sound an awful lot like yours.

Out of curiosity...
I know it's generally assumed (by me as well) that the starting trip costs only changing walking and car will have any effect, because as stated (I think by Mott as usual) "those are the only 2 types generated by residential".
I'm wondering if anyone actually tried messing with them?

Yes, I did.  As Mott implied, other types have no effect whatsoever.  When Sims leave their houses, they do so either by walking or using their cars.  Even if a transit stop is right in front of a Sim's house, the Sim has to walk to it - one tile needs to be crossed.  So these are the only possibilities for starting a trip.  And as Mott and I found, "starting a trip" means starting it from the beginning, not just a segment of it.
Title: Re: Traffic Simulator Z Development
Post by: schack on November 06, 2009, 03:30:04 PM
Yeah, I'm using 1.2 beta 3.

What I did notice though, was that when building a city from scratch and starting with pretty much nothing but NAM and then adding all my plugins after a bit, it seemed to work perfectly. So I think I'll just do that from now and then pray to the higher computing powers. It's really puzzling, but with this many plugins it seems virtually impossible to figure out.
Title: Re: Traffic Simulator Z Development
Post by: z on November 06, 2009, 04:05:04 PM
Yeah, I'm using 1.2 beta 3.

Ah yes, you mentioned this at the beginning of your original post.  I guess it just didn't register.  Sorry about that.  &mmm  But you've now come up with what I think is the crucial information:

Quote
What I did notice though, was that when building a city from scratch and starting with pretty much nothing but NAM and then adding all my plugins after a bit, it seemed to work perfectly. So I think I'll just do that from now and then pray to the higher computing powers. It's really puzzling, but with this many plugins it seems virtually impossible to figure out.

This would definitely tend to say that it's not a simulator problem.  But don't give up yet - there are only a few plugins that can result in this type of problem, and they're all in the "mod" category.  Your city may need to reach a crucial size before they start interfering with the simulator, which would be why you don't see this in a new city.  So, do you have any traffic mods installed?  Or any mods that affect demand?

If the answer to both of those questions is "no," then try restoring half your mods at once, and see if you get the problem.  (This can be done in existing cities, since mods don't involve lots.  I'd recommend trying this in the city that's giving you problems.)  If you do, remove half of the mods and try again.  If you don't, put in half of the mods that you didn't choose the first time and see if you get the problem.  Repeat until the culprit is found.
Title: Re: Traffic Simulator Z Development
Post by: schack on November 07, 2009, 02:35:32 AM
Hehe, that's actually exactly what I was doing and how I caught that part.
I'd started out a new city in a test region with just NAM, built it up to 20k and then started moving in plugins slowly. After restoring half my plugins and still not seeing an issue, I decided to restore them all... and I couldn't replicate the problem. Mind you, my city started messing up already at 8k inhabitants but just basically kept it up.

What I've done now is Obliterate it and start again with nothing but NAM/SAM/RHW, and following the contours of the land from my previous settlement, recreate my transport network. Then restore all plugins and go ahead. And it works, the city's flourishing and people are driving where the jobs are, preferring closer jobs but certainly not unwilling to commute to the riverside industrial area. So with this workaround I'm a happy man.

And that's why I said I doubted I'd ever find the true reason for this, because that would mean I would have to build a city from scratch for each and every plugin I have :O

But it's interesting in that it seems something can mess up the traffic sim when you start a game, but not in a running game...
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 07, 2009, 03:22:04 AM
Little question, Schack: you do not mention the CAM at all does this mean that do not use it? (I have the same problem as yours, so I try to find similarities and differences)
Title: Re: Traffic Simulator Z Development
Post by: z on November 07, 2009, 05:43:12 AM
Traffic simulator aficionados, rejoice!  &dance &dance &dance ()flower() ()flower() ()flower() &hlp &hlp &hlp  Certain secrets of the Maxis traffic simulator, last heard in the hallowed but long-deserted Halls of Maxis, have been rediscovered!  :o "$Deal"$ :o  Formerly known only to a select group of Maxis programmers  ()meeting(), these secrets are about to see the light of day.  :sunny:


It all started when...  (You know it's going to be a long post when it begins "It all started when..."  But knowledge comes at a price!  ::)  Patience, dear readers, patience...  :sleeping:)

Anyway, it all started when Jason challenged me to a duel.  ?$%kar&%h  (No, that can't be right.  ???  What was it?  ()what()  Oh yes!  &idea) to prove an assertion I had made based on experiments I performed when I first built Simulator Z.  I had found that increasing the pathfinding heuristic above .003 would produce abandonment in various situations.  Jason's response was:

I would like you to proove this...  I have not had any problems what-so-ever with abandonment in my cities due to the PH [pathfinding heuristic] being higher than yours.  If you are so confident that the PH causes abandonment, proove it with Simulator Z and raise the value to 0.009 and show me the abandonment.

So I did exactly what Jason had asked.  I took Simulator Z, raised the PH to .009 and showed him abandonment where none had existed before, and I did it all publicly in this long post (http://sc4devotion.com/forums/index.php?topic=5382.msg283986#msg283986).  However, in a later post, Jason stated the following:

Quote
It would be interesting to see how this one change in the PH effects other play styles.  There is a big question of why do I not get abandonment with a PH of .009 but you do?  Maybe there was an anomoly in your experiment?  I simply have not seen anything like that happen in my cities other then when I was using the MAXIS Default Simulator.

I am not trying to challenge your test, but I think it needs more testing.

OK.  I'm sure that there are other skeptics out there besides Jason.  So I designed a number of new, different tests.  And as they say, "Around every silver lining, there's a dark cloud." ()testing()   "Inside every dark cloud, there's a silver lining." :)  And in this case, the silver lining was unexpected revelations about the inner workings of the traffic simulator.

Disclaimer:  These tests were performed only at Jason's request, and were merely designed to provide further evidence for previously made assertions about properties of the traffic simulator in general.  They are not designed, nor is it claimed that they show, anything in particular about any particular simulator; specifically, they are not claimed to show the fitness of any simulator for any particular purpose.  They do not claim to show whether a simulator is "good," "bad," "realistic," or a "sandbox simulator."  These tests merely illustrate the function of particular parameters in SC4 traffic simulators in general.  Actual simulators were used because this helped illustrate the effect of these parameters most effectively.  No Sims were harmed in the running of these tests.

OK, now that we've gotten the legalese out of the way, let's move on to the tests.

We start once again with the Near South Side of Chicago.  Jason raised the question of playing style.  Since all of my cities are arguably built in my playing style, that's the only style I can test directly.  However, there are other factors that come into play here.  First of all, as I mentioned earlier, this is not really "my" style, but is a reconstruction of an actual city, built and zoned to scale.  This is not an infrequent way of playing, and anyone can duplicate tests such as these using large cities on large tiles.  Secondly, if the tests can successfully illustrate principles of traffic simulator operation (which is their goal), then it really doesn't matter what playing style is used, or even if it is actually used by anyone at all.  For even in the latter case, the principle that has been discovered or proven can be applied to understand the workings of any city built with any style of play.

[Update:  Since I began writing this post several days ago, ldog (Lenny) has published confirming experiments of his own design with a custom-built simulator in his thread (http://sc4devotion.com/forums/index.php?topic=9179.msg282572#msg282572).  This would seem to address both the playing style and anomaly issues.  Jason has accepted this, but quite reasonably, still wants to know why he hasn't seen these effects with Simulator A.  In ldog's thread, he asks ldog, "Is it possible for you to test a City with Simulator A and show this effect happening?"  This post addresses that issue; it's actually somewhat coincidental that I had already done the following tests.]

We would like to make these tests as different as possible from the first set we did with Simulator Z, but designed in a way that they end up testing the same properties, most notably the Pathfinding Heuristic (PH).  So for all of the tests in this post, we will use variations of Simulator A (Hard).  First of all, this seems very appropriate, since this whole issue arose over the question of what function the PH played in the workings of Simulator A.  Secondly, reproducing the same effects in both Simulators A and Z would be further proof that the effect shown in the previous tests was not just some anomaly, as hypothesized by Jason.

But some may ask, Is it fair to use the Hard version of Simulator A on a city with a population of two million?  After all, the NAM documentation recommends that the Hard version be used only on cities up to about 250,000 Sims, while the Easy version is recommended for cities less than half the size of the Near South Side.  The answer is yes, it's fair, because we are not expecting the simulator to perform properly.  We are deliberately testing it out of spec to see if we can find evidence of problems that might only show up occasionally, or that might even show up frequently, but might be missed due to other factors.  If we don't test things out of spec, we run the risk of ending up in a position similar to that of the engineers who built the first Tacoma Narrows Bridge (http://www.youtube.com/watch?v=3mclp9QmCGs).

We start with an unmodified version of Simulator A (Hard), and we use the same starting point as before for the Near South Side - January, 433.  We run the game for 12 years and take a look:

(http://img509.imageshack.us/img509/9548/jnssa.jpg)

I'm sure that the results here are not unexpected.  What's interesting is that if you compare this picture with the second picture in the previous test post, which showed Simulator Z modified to run with a PH of .009, you see that virtually all the buildings that were abandoned in that picture are abandoned in this picture as well.  There are also additional buildings that are abandoned in this picture as well.  There seem to be three main possibilities for the abandoned buildings in the current picture:


This picture alone does not provide enough data to choose between these three options.  Meanwhile, I've noticed that the speed of the game running this city on my computer under Simulator A is the same that it's been in previous tests - three game years per hour in Cheetah mode, which is half of the six game years per hour that I've found running under Simulator Z.  That's the game as a whole; the actual Simulator A running time seems to be about four times as long as Simulator Z.  In a later test, for the first time we'll find out exactly what's responsible for that large difference in speed.

Now we run the game for an additional 13 years, making 25 years in total, which means that this single test has taken more than eight hours.  The abandonment is essentially the same, so there's no need to post another city picture.  But now we have enough data for some interesting graphs:

(http://img43.imageshack.us/img43/6047/jnssd.jpg)

Again, we have the same pattern of rising population that we had in the first testing post.  That turned out not to be a good thing there.  What about now?

(http://img18.imageshack.us/img18/735/jnsse.jpg)

Sure enough, we have almost the exact same diverging population lines as in the first testing post.  Once again, high-wealth Sims are deserting their residences (presumably fleeing to the suburbs), while their former residences are being occupied by a larger number of low-wealth Sims.  In the previous test, this change appeared to be linked solely to the change in the PH, as that was the only change made to the simulator.  So it's beginning to look like the PH does at least play a factor here.

Now some skeptics may say, "But the PH doesn't behave like that!  At least not in Simulator A.  Are you sure you have Simulator A installed properly?  Are you sure that there's not one of your many versions of Simulator Z hanging around, overriding it?"  Well, it's easy enough to show that this is indeed Simulator A.  Here is the Traffic Volume Graph:

(http://img97.imageshack.us/img97/4030/jnssc.jpg)

The left side is Simulator Z; the right side is Simulator A.  There are some very obvious differences.  Car usage is higher is Simulator Z, simply because that's the way the simulator is set; still, not counting pedestrian traffic, car traffic comprises only about 20% of total traffic in this city under Simulator Z, compared to 11% for Simulator A.  Bus traffic is almost nonexistent under Simulator Z simply because this city was built with a much older simulator, and subway and bus lines are almost completely congruent.  In Simulator A, bus traffic exceeds car traffic; as we will see in later examples, the bus traffic in this city in Simulator A is mostly due to the fact that buses in that simulator do not contribute to traffic or congestion.

Speaking of congestion, here's the congestion minimap for the unmodified Simulator A:

(http://img18.imageshack.us/img18/9352/jnssb.jpg)

Congestion is pretty bad, but then it should be; this simulator is operating way out of spec.

That completes the testing of the unmodified version of Simulator A.  There definitely seemed to be some indication that the PH is involved in both abandonment and downgrading, but how much?  And can we be sure?  Yes, we can, but to see why, and to answer the first question, we need to do different tests.

One possible explanation for some of the effects that we have observed is congestion and commute time limitation.  Of course, congestion can cause such effects only if there is a commute time limitation.  So for the next experiment, we raise the maximum commute time of Simulator A to the level of Simulator Z, which is effectively infinite.  With this modified simulator, no abandonment or downgrading effects can be attributed to commute time limitations, because there are none.  So if the commute time limitations were responsible for the abandonment and downgrading, we should now not see either of those two.  Making the commute time unlimited should give us a "sandbox simulator," right?  We'll soon see.

Capacities of Simulator A are similar to those of Simulator Z (Low), which has no abandonment or downgrading problems in this city.  However, Simulator Z's rail capacities are somewhat higher.  So that we can completely rule out different capacities as being the cause of different simulator behaviors, we give our modified version of Simulator A (Hard) the capacities of Simulator Z (Low).  Now we restart our city in January, 433 again, and run it for 7 years.  Here is the result:

(http://img22.imageshack.us/img22/957/jnss1.jpg)

This is interesting.  Even though the maximum commute time is now unlimited, abandonment is almost as bad as in the previous test.  It doesn't look like making the maximum commute time unlimited creates a "sandbox simulator."  Those really dark buildings are all truly abandoned due to commute time, too.  As in the previous testing post, I checked them all out.  Here's just one example:

(http://img692.imageshack.us/img692/6986/jnss2.jpg)

How can they be abandoned due to commute time, if commute time is unlimited?  There are only two ways this can happen.  If there aren't enough jobs for these Sims, they'll abandon their residences and leave town.  But we saw from the picture at the beginning of the last testing post that the city was in perfect health under Simulator Z.  And then there are all those graphs, too.  So there are plenty of jobs in this city.

There's only one other possible explanation:  The pathfinding heuristic is too high.  The jobs are there, but the Sims can't find valid paths to them.  It looks like the PH is playing a very big role in abandonment here, being responsible for at least most of it.

Meanwhile, I mentioned earlier that one of the tests would show what was responsible for the large difference in speed between Simulators A and Z - basically a factor of four in this city.  I had suspected that it had something to do with the Congestion vs. Speed Curve, as the implementation of this curve has a direct effect on the speed of the A* algorithm.  But although this is true, it turns out that there is a factor that has an effect many times greater on the speed of the simulator.  It's the maximum commute time.

Now if you think about it, you might thin, "That's reasonable - with a higher maximum commute time, the pathfinder can explore more paths, which means that there's more work for it to do, which means that it will run slower."  But it turns out to work just the opposite way:  Other things being equal, then the higher the maximum commute time, the faster the simulator runs.  This effect dwarfs all other effects on simulator speed.  Of course, there comes a point where raising the commute time will no longer raise the simulator speed; where this point is varies by city.

I discovered this when I ran the current test.  Whereas the game had always run at about three years per hour in this city before when using Simulator A, now it was running at a bit more than six years per hour, which is a bit faster than using Simulator Z.  (This makes sense because once the maximum commute times have been equalized, Simulator A's higher PH will cause it to run slightly faster than Simulator Z.)  This means that Simulator A itself was running about five times as fast as it had before I raised the maximum commute time.  This has since been verified repeatedly.

At first I thought that this made no sense at all.  Then I realized what was happening.  With a low maximum commute time, the simulator was having to try extra hard to get the Sims to their jobs before running out of commute time.  With a high maximum commute time, the simulator was freer to pick the first valid route that came along that met the PH criteria.  This also leads to a wider range of routes.  So with a higher maximum commute time, there was actually less work for the simulator to do.  Apparently, a lot less.

I remember when I installed the NAM for the very first time and switched from the Maxis simulator to one of the NAM simulators on a large tile.  There were many benefits, of course, and among them was that my game started running faster.  I didn't understand much about how anything worked at that point, so I didn't think about it a lot then.  But now I see why it happened.

So what's the benefit of a low commute time?  I can see none.  If commute time is going to be great enough so that abandonment does not occur, then you might as well raise it way up and make the game run faster.  This may decrease congestion, but if you want more congestion, the best way to get that is to lower network capacities, as doing so has no unexpected side effects.

So that's what the city looks like after seven years.  Was that enough time for the full effects of the simulator switch to manifest?  We'll run the game for another 23 years, for a total of 30 years for this test, to find out:

(http://img97.imageshack.us/img97/745/jnss4.jpg)

Things look pretty much the same.  Some abandonment in the smaller buildings in the upper right of the picture has cleared up, but one of the big residential towers has gone from completely healthy in the previous picture to abandoned now.  This looks like a typical abandon/reoccupy cycle.

What about the rest of the city?  Here's another neighborhood:

(http://img59.imageshack.us/img59/9765/jnss5.jpg)

Notice that one instance of the Comfort Arms is selected.  Most instances of this building in this picture are dark gray, meaning downgraded, while a few are black (along with some other buildings), meaning abandoned.  The downgrading is new, as we'll see in the following graph.  It's part of the whole abandon/reoccupy cycle going on in this city.  Here's the Pop & Jobs graph:

(http://img692.imageshack.us/img692/5050/jnss6.jpg)

Once again, we have the diverging lines, with the same meaning as before.  And what they show certainly corresponds with the picture above.  It looks like raising the maximum commute time didn't buy us much in this city, at least in terms of abandonment and downgrading.

Finally, let's take a look at the Traffic Volume Graph:

(http://img43.imageshack.us/img43/8336/jnss7.jpg)

This looks basically the same as the Traffic Volume Graph from the previous test, with one exception:  Bus traffic is now less than car traffic, instead of greater.  This is a direct result of increasing the commute time.  With a longer commute time, the pathfinder is able to use less congested routes for the Sims, such as subways, and there is less necessity for putting them on buses, which effectively have infinite capacity in Simulator A.

So if making the maximum commute time unlimited doesn't solve the abandonment problem, what's causing it?  None of the abandonment and downgrading we have seen in this set of pictures has come from commute time limitations, since there are none.  Is there a single parameter in the traffic simulator that actually is causing this problem?

Not surprisingly, the answer is "yes."  It's the same parameter that caused all the abandonment in the modified version of Simulator Z in the previous testing post:  the Pathfinding Heuristic.  How do we prove this?  It would seem that the easiest way would be to start with an unmodified copy of Simulator A and lower the Pathfinding Heuristic from .009 to .003, leaving absolutely everything else unchanged.  So that's what we do.  We start at the same point, and we take a look around after 15 years:

(http://img692.imageshack.us/img692/8831/j2nss1.jpg)

I found this to be a very surprising picture.  In the previous testing post, I had shown that raising the pathfinding heuristic in Simulator Z resulted in abandonment where there had been none before.  This was not surprising, since Simulator Z has an effectively unlimited maximum commute time.  But Simulator A's maximum commute time of 8.5 minutes (one way) has been kept intact here, and there are only two abandoned buildings:  the Comfort Arms on the upper edge of the park, and the tall building near the top of the picture.  (The Al  Attar building lower down looks dark, but it has merely been downgraded to low wealth.)  Compare that with the first picture in this post, where there are about a dozen abandoned buildings.  The only difference in the simulators used is in the value of the pathfinding heuristic.

The above picture is after 15 years.  What happens if we run longer?  Does the abandonment get worse, better, or stay the same?  We run for 10 more years, for a total of 25 years, and take another look around:

(http://img692.imageshack.us/img692/5609/j2nss2.jpg)

Another surprising picture:  The abandonment is gone completely.  Again, this is just standard Simulator A (Hard), with the only change being that the PH has been reduced from .009 to .003.  Although this simulator was designed for cities with a maximum population of about 250,000, it seems to be doing quite fine on a city eight times that size, once we reduce the PH.

What about the graphs?  We would expect these to look quite different from the graphs in the previous two tests, although we would not expect them to look identical to Simulator Z's graphs.  The simulators are still different in other ways.

First we start with the cumulative RCI population graph:

(http://img692.imageshack.us/img692/4799/j2nss3.jpg)

As before, there's a rise in population in the middle of the graph when we switch from Simulator Z to Simulator A, but this time it's much less pronounced.  (The rise is preceded by a brief dip, which is where the temporary abandonment occurs.  As a population rise in the previous tests always had negative implications, this would seem to be a good sign.  For details, we look at the Pop & Jobs Graph:

(http://img97.imageshack.us/img97/2720/j2nss4.jpg)

Sure enough, the wide divergence between the R$ and R$$$ populations has disappeared.  In both previous tests in this thread, and in the test of the degraded Simulator Z in the previous thread, the divergence was always present.  So it's been present in the three tests where the PH was .009, and absent in the two tests where the PH was .003.  Based on these five tests, it certainly appears that the higher PH not only causes more abandonment, but also results in the city's being less attractive to high-wealth Sims and more attractive to low-wealth Sims.

Looking at the graph more closely, we can see a little bit more of what's been going on.  There was an initial drop off in high wealth Sims, which was presumably accompanied by abandonment.  The most likely cause for this is the reduced maximum commute time; routes that worked before were suddenly too long.  But the pathfinder is much smarter now, and over the next 25 years, it gradually found paths for everybody, so that at the end of this period, the population of high-wealth Sims is the same as before the drop.  There's just a tiny drop right at the end of this period; this is most likely not the beginning of a reverse trend, but simply a small fluctuation indicating that the rise has leveled off.

So there's essentially no net change in the R$$$ population.  However, during this period, the R$ population rises, while the R$$ declines, though by a smaller amount.  This change is due to other differences between the two simulators.  Based on previous experience and also on checking out various buildings, what's happening here is that there has been some downgrading of buildings from R$$ to R$.  However, this is unrelated to the PH, since the PH is identical on both sides of the graph.

Let's take a quick look at the Traffic Volume Graph:

(http://img97.imageshack.us/img97/5990/j2nss5.jpg)

It looks very similar to the previous one.  So traffic volume patterns really haven't changed significantly here.  This seems quite natural, until you remember that the previous graph was from the experiment where Simulator A had been modified to have an unlimited maximum commute time, whereas in this experiment it has the standard 8.5 minutes (one way) commute time.  In both cases, bus usage (which is used here as an escape valve for too much congestion) dropped.  This is more evidence that dropping the PH is similar in some ways to extending the commute time.  This is also one reason Nate's city worked fine with the CAM traffic simulator, which has a very large PH of .0465 (more than five times that of Simulator A); the large PH was greatly offset by a large commute time of 30 minutes one-way.

Here's a congestion minimap of the modified Simulator A:

(http://img18.imageshack.us/img18/3869/j2nss6.jpg)

There's still plenty of congestion, even though there's a low PH, no abandonment and no loss of R$$$ population.  Compare the above graph with the congestion graph of the unmodified Simulator A, which was displayed earlier in this post, but is reproduced directly below for easy comparison:

(http://img18.imageshack.us/img18/9352/jnssb.jpg)

As you can see, there's somewhat more congestion here.  The lesser congestion in the first picture is a result of the smarter pathfinder rearranging the routes of the Sims so that they all can get to their jobs within 8.5 minutes.  Another way of putting this is that a lower PH makes congestion more of a motivating factor for the pathfinder in finding faster routes for Sims.

Finally, for comparison, here's the congestion minimap of the recently introduced Simulator Z Classic:

(http://img29.imageshack.us/img29/6829/zclassic.jpg)

It looks extremely similar to the congestion minimap of the unmodified Simulator A directly above, although if you look closely, you can see that there's a bit more congestion.  I introduced Simulator Z Classic with a (hopefully) somewhat amusing post, but as you can see, it's no joke.  Its network capacities are all no more than half that of the version of Simulator A whose congestion minimap is displayed directly above.  This means that congested networks with similar congestion levels in Simulator Z Classic are carrying about half the traffic as their counterparts in Simulator A (Hard), at least in this city.

Does the similarity in congestion minimaps mean that Simulator Z Classic is roughly equivalent to Simulator A (Hard)?  Not at all.  It simply means what you can see:  In this city, their congestion minimaps are very similar.  In other cities, that may or may not be the case.  What I think this does show is that the combined power of a low PH and an unlimited commute time can greatly reduce the need for network capacity.  At the same time, Simulator Z Classic is like all other versions of Simulator Z in that abandonment due to commute time is essentially nonexistent, as is downgrading.  This last feature, of course, is dependent on many other factors besides the traffic simulator; the Near South Side has been designed and maintained to attract as many high-wealth Sims as possible.  (Disclaimer:  I am not a particularly noteworthy game player, so there is undoubtedly a lot more that could have been done in this area.)

At the beginning of this post, I promised that I would reveal new secrets about the inner workings of the traffic simulator engine.  I'll summarize what I have shown here:


So I think I have demonstrated that the same effects I have shown happening in Simulator Z can also happen in Simulator A.  But obviously, they don't happen all the time, as Jason has pointed out.  So now it's time to answer his question:  Why hasn't he seen these effects?  I have also gone through the entire testing thread he referenced, and certainly, I think that the general feeling any reader of that thread would get would be that this simulator was working quite well, was a big improvement over previous simulators, and had no major problems.  I think one summary Jason posted is also relevant:

Quote
Telltale signs that the Simulator is unbalanced:
1.  Abandonment when there is sufficient demand and jobs available.
2.  Sims taking obscure paths.
3.  Possible Abandonment/Repopulation cycle. (can be caused by other things aswell, such as poorly designed network structure, other Simulator issues, etc.)
There are others aswell but these are big ones.

I would agree with this completely, and in fact, this is what I have concentrated on showing in this post.  Why didn't Jason see any of this?

There are two parts to this answer.  The first part is that the cities tested tended to be on the small side.  As I mentioned earlier, performance differences in the simulator tend to manifest exponentially with city size.  Mott made mention of the exponential nature of A* in October, 2007, months before the tests began.  Yet from what I can tell, all of the test cities except one had a population less than a million, many of them much less, which made them a size in which it was far less likely for them to run into problems with a PH of .009.  This is especially true since many of these cities were originally built with a traffic simulator with a much larger PH; in such cases, using Simulator A with its PH of .009 would cause abandonment due to commute time either to decrease markedly or disappear entirely.

The second part of this answer concerns the city with the biggest population - Nate's, which started out with a population of over two million.  Although as Jason has pointed out, the congestion data view is unreliable, I have found enough data in Nate's posts to be able to show that either all or virtually all of his abandonment was caused by the PH.  At the same time, showing this unveils the presence of the Congestion Data View Bug, not only the one in the congestion data view, but also the related one in Simulator A itself (which has since been fixed).  However, showing this will take a separate post, as I need a break now (as do my readers, assuming there are any left  ::)).

Jason, do you have a record of exactly what capacity numbers were used in your test simulator?  I saw some of the numbers mentioned, and in one place you mentioned that the simulator had capacities close to what is now the Medium version of Simulator A.  However, if I had the exact capacities, I could be more precise in my explanation.

I hope that I have provided convincing evidence of what I have found; any questions are welcome.  The follow-up post concerning Nate's city will come as soon as possible.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on November 07, 2009, 06:15:15 AM
Interesting post, though... I still have a question: what affects how frequently the game "refreshes" its paths for the entire city? Say you bulldoze a road, and you get the "flying car" bug using the path query tool (and in the congestion data view it still shows up)... how long does it take, usually, before the game refreshes itself and corrects all the paths for its Sims when they travel?

Does the PH affect this, or is it something else within the simulator, or even as a direct result of computer speed?
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 07, 2009, 06:26:41 AM
One dumb question, which I think needs to be asked.
Can a building become abandoned due to it's desirability factors changing? And if so, is that abandonment still defined as "Abandoned Due To Commute Time"? I only ask because I can't recall ever seeing an abandoned building with "Abandoned Due To Pollution", or any other reason aside from commute time. Perhaps all abandonment is blamed on commute times?
Taking a look at your pics, I can see you're using CAM, which has stronger desirability requirements in place, to prevent abandonment, but even those aren't foolproof. Overly congested transit networks deminish an area's desirability, which would cause much of the abandonment issues you've shown.
Not to discount your tests by any means, I just think we still don't have enough information. Perhaps get pics of the area in question's desirability before & say 10 years after switching traffic sims? Especially R$$$.
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 07, 2009, 06:43:40 AM
This was discussed in Lenny's thread not so long ago. :)


There are only five of them in the game:

  • Abandoned due to lack of power
  • Abandoned due to lack of water
  • Abandoned due to low desirability
  • Abandoned due to commute time
  • Abandoned due to low demand

The third one is the one that you would get due to low customers in a commercial building, or due to any other desirability factor being too low (all in all, for any RCI type due to the desirability falling below the abandonment threshold).

The fourth one is the only one that you'd normally get in residentials, unless you cut off power or water.

The fifth one is the one you'd get if the overall demand for that RCI type is negative, and that can occur for all RCI types.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 07, 2009, 06:45:30 AM
 A real eye opener of a post here Steve  :o

Thanks for all the time and efforts you put into this highly informative tests of the traffic sims..
Back a long time ago, when I helped you run all those comparison tests of the different traffic sims.
i often wondered later what the true reasons were for sim Z running faster than the other despite
its more precise PH setting than the others..  :-\ i really appreciate you solving that little mystery for me  &apls

I think your post here is obviously going to generate a lot of further discussion about the traffic sims as you
have presented many new concepts which we did nt have a handle on previous to your testing here..
I greatly look forward to those discussions in your thread here..

your good friend, Brian
Title: Re: Traffic Simulator Z Development
Post by: z on November 07, 2009, 06:50:30 AM
Interesting post, though... I still have a question: what affects how frequently the game "refreshes" its paths for the entire city? Say you bulldoze a road, and you get the "flying car" bug using the path query tool (and in the congestion data view it still shows up)... how long does it take, usually, before the game refreshes itself and corrects all the paths for its Sims when they travel?

Does the PH affect this, or is it something else within the simulator, or even as a direct result of computer speed?

What you're really asking is, "How often does the traffic simulator run?"  The answer is about once every four months, more or less.  The exact frequency is somewhat dependent on city population, but nothing else.

There are some exceptions here.  For example, when you first load a game, it may be well over a year before the traffic simulator first runs, but then it will resume its normal schedule.  That's the only exception I know of that affects your case.  Other exceptions may affect when certain parts of the traffic simulator run.

One dumb question, which I think needs to be asked.
Can a building become abandoned due to it's desirability factors changing?

Possibly, to the extent that desirability affected demand.

Quote
And if so, is that abandonment still defined as "Abandoned Due To Commute Time"? I only ask because I can't recall ever seeing an abandoned building with "Abandoned Due To Pollution", or any other reason aside from commute time. Perhaps all abandonment is blamed on commute times?

Definitely not.  There's a whole category of abandonment due to lack of demand.  There are only three ways you can get abandonment due to commute time:  1) There are no valid jobs for your Sims to reach.  This is fairly rare.  2) Your Sims are unable to reach valid jobs within the maximum commute time limit.  3) Due to the setting of the PH, the Sims are unable to find valid paths to their jobs.

Quote
Not to discount your tests by any means, I just think we still don't have enough information. Perhaps get pics of the area in question's desirability before & say 10 years after switching traffic sims? Especially R$$$.

Assuming what I say is true about abandonment, do you still think we still don't have enough information?

I see that Tage has posted as well, confirming what I said...
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 07, 2009, 07:45:35 AM
Yeah, I was in the process of modifying my earlier post... after talking with Tage.
I'll read over your tests again after a good day's sleep...
But I already know that the only way for me to be truly convinced is to test it myself, in order to analyze every little question that pops up in my mind, in real time. So... looks like I have a new city to build, as soon as I wrap up my current project...
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 07, 2009, 11:11:58 AM
 &apls
Wow. I really don't even have much of anything to say for a change :P
Great job testing and documenting (I think this gets me out of doing the last test Jason asked me for :D )
 :thumbsup:
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 07, 2009, 01:55:35 PM
Wow, z, that's the most animated intro I've seen of a post of yours.  :P

Good job on the investigating!   :thumbsup:  I do agree that higher commute time = more paths available (if any).  The initial gut feeling is that will lead to more CPU power needed, but the performance of Simulator Z refuted that.  We've been saying all along that Simulator Z runs faster than pretty much all other simulators out there and it has a much higher max commute time.  Why didn't any of us see that connection between the two any sooner?   ???
[Edit: jplumbey's post below casts a shadow of doubt on what I've said in this post.]

The "low" commute times causing abandonment makes sense.  But that counter-intuitive higher max commute time = faster simulator makes sense also, after reading that line a few times.  If the max commute time were set to the minimum time that one commuter could to get to an available job (ignoring congestion), the simulator would find that job sooner than if it had to do an exhaustive search of the city tile of paths within the max commute time.  If the max commute time were set to one minute less, the simulator wouldn't find a path, and it would have to do the exhaustive search (leading to more time because of more calculations).
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 07, 2009, 08:05:04 PM
Anyway, it all started when Jason challenged me to a duel.  ?$%kar&%h  (No, that can't be right.  ???  What was it?  ()what()  Oh yes!  &idea) to prove an assertion I had made based on experiments I performed when I first built Simulator Z.  I had found that increasing the pathfinding heuristic above .003 would produce abandonment in various situations.  Jason's response was:

So I did exactly what Jason had asked.  I took Simulator Z, raised the PH to .009 and showed him abandonment where none had existed before, and I did it all publicly in this long post (http://sc4devotion.com/forums/index.php?topic=5382.msg283986#msg283986).  However, in a later post, Jason stated the following:

OK.  I'm sure that there are other skeptics out there besides Jason.

Before I even read your post I have to comment on this...

I did not "challenge you to a duel" and I think you should stop acting that I am "dueling" with you.  I am tired of your attitude and the way you relentlessly attack my work with impunity.  And due to your attitude, yes I am very skeptical of your tests, I will be honest and tell you when I read them I feel bias in them from you.  Especially when you are trying to prove the "legitimacy" of your work compared to Simulator A.

Please realize that I have not been attacking your work and I am only defending mine.  I have not attacked your work and I would greatly appreciate that you stop attacking mine the way you have been.  If you were to stop and maybe change your attitude towards me a little bit then things wouldn't be so tense.  Believe me I have been trying really hard not to fight with you and give you some respect, unfortunately I do not feel you see it, nor are you even trying to give me that same respect.

I am sorry you have seen this as some kind of duel....  Where it is clearly a one-sided duel and one I am not trying to participate in but collaborate in a group effort.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 07, 2009, 09:06:35 PM
I have a problem with your assertion that "Higher Max Commute Time" = faster game speed.....  You have pointed out that Simulator A runs slower than other Simulators, which is true.  So, then if Maximum Commute Time is what creates this "slowness" why does Simulator A run slower than the default Simulator when Simulator A has a Max Commute Time almost 3x higher?

Your post is interesting.  You have shown that the 0.009 value can cause abandonment in any Simulator, but still there are questions why it happens in some cities but not all.  You again have attacked me in trying to say I have missed it... but it is hard to say I miss it when I don't run into the problem.  Your entire post seems hostile towards me.

I also disagree with your assertion that the City is "less attractive" to R$$$ Sims and more attractive to R$ Sims.  The PH should not be effecting the demand as this statement would suggest.  What is more likely is this is a side-effect of the Pathfinding itself, something more along the lines of something I posted earlier where the buildings are dilapidating due to the number of paths in that building being "not valid" but not enough to the point where the building has abandoned.  Quoted below is that theory I had posted over a week ago:

The relevant part in this quoted post is where it discusses the part of the theory is where the game determines how to abandon a building.  Dilapidation would come into effect here because it would create a buffer zone between "normal occupancy" and "outright abandonment".

I dont begin to trivialize this as "elementary"...  I will say I do not know exactly how A* is used in SC4, but we do know it is a function in a larger equation or a function of a series of equations which determine the  IF, HOW, WHERE, WHEN, etc. for a Sim to reach thier destination.  What you have read only strengthens what my belief of the PH is used for, if in fact what you have read is true.

To me...

PH is the HOW of the Simulator.  It is what the Simulator uses to determine WHICH path to choose to get from point A to point B and the value of the PH, from my understanding, is how accurately it compares the routes that it finds.  But, this has no direct relationship to IF the path it chooses is a successful or unsuccessful path.  Now, from time to time depending on the accuracy of the value it may select a route that is slightly "slower".

Speed is the cost per tile, we know the Simulator will use Speed with multiple variables like the CvS, Intersection vs Speed properties and more to determine the cost of each route it checks.

The IF part, is where abandonment will come into play, and it should be as simple as an IF/THEN statement for the Simulator to compare the "best" route it finds for the Sim against the Maximum Commute Time.  If the total round trip cost of the trip is over 17, then the building becomes abandoned.

Now, the part that makes this theory dicey is the fact that there are 1000s of Sims in one building, with multiple destinations.... I do not know how MAXIS has handled this but it is very easy to see that in many cases your buildings dont have all of thier Sims commuting.  One might chalk this up to so Sims are kids and go to school instead of work, etc.  But maybe there is another reason for this, a more practical one in reference to the Traffic Simulator.  In a building of 1000s of Sims, even 100s of Sims, there will be routes that work and routes that dont.  The way I believe that MAXIS has handled the failed routes is by comparing the number of successful and unsuccessful routes from the same building and if the number of failed routes reachs a certain threshhold, such as 40% for example, then the building will become abandoned.  But, by the same token if the building has a much higher percentage of successful routes then the building will stay inhabitted and depending on how many unsuccessful routes are found could be used to determine the descrpancy between "building occupancy" and "building capacity".

So for the sake of an example for those who don't understand my theory:  (this will in no way be totally accurate, but an idea of how this may work)

Lets take a building that has a
Building Capactiy = 1000 Sims

Now, the 1000 Sims in the building will search for routes to the random destinations they have chosen for work.  The Simulator will do it's work, calculate the cost of each trip, compare them using the value of PH then compare the cost of each the best route for each Sim with the Commute Time allowed.

After the routes have been compared and the best ones for each of the 1000 Sims has been compared to the Commute Time, the Simulator finds that 700 or the 1000 Sims found a successful route to work.  Which, surpasses the 60% requirement (just an example remember) for the building to be considered "Occupied" so the building does not abandon.

So, you will probably see 700 Sims leaving the building and following thier route to work.  But when you query the building, it might say there are 893 Sims occupying the building.  Why are the other 193 Sims still in the building you may ask?  Well, it may only take a percentage of the Sims who did not find a successful route out of the building, but left the others in to possibly increase population for stage caps, demand and other purposes in the game that these Sims would effect.

It is a theory, but to be honest I think this is how the game really deals with pathfinding, abandonment and how they two together act to effect other parts of the game.  It is probably by no means a "perfect" description of how it works, but a general idea and I am sure there are other things that are not taken into consideration that take this basic theory and make it more complex under the same basic prinicpal I have just described.
Title: Re: Traffic Simulator Z Development
Post by: catty on November 07, 2009, 10:42:01 PM
Can I make a suggestion, the old SimCityscape site has quite literally 1000s of cities ranging from ones with only a few hundred sims to ones with millions of sims all of which can be downloaded.

http://simcity.ea.com/scape/index.php

If @jplumbley and @z were to select one of these cities as a test city that the testers could all go and download and set up some agreed test conditions;

a. Simulator A or Z
b. contents of plugins
c. changes allowed in the city
d. how long to run and what snaphots you want taking and when
e. ...... and so on

I for one would be happy to act as a tester and hopefully it might give us a clearer idea of the difference between SIM A and SIM Z and what's happening in the game.

Cathy
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 07, 2009, 11:38:51 PM
I have a problem with your assertion that "Higher Max Commute Time" = faster game speed.....  You have pointed out that Simulator A runs slower than other Simulators, which is true.  So, then if Maximum Commute Time is what creates this "slowness" why does Simulator A run slower than the default Simulator when Simulator A has a Max Commute Time almost 3x higher?

Your post is interesting.  You have shown that the 0.009 value can cause abandonment in any Simulator, but still there are questions why it happens in some cities but not all.  You again have attacked me in trying to say I have missed it... but it is hard to say I miss it when I don't run into the problem.  Your entire post seems hostile towards me.

I also disagree with your assertion that the City is "less attractive" to R$$$ Sims and more attractive to R$ Sims.  The PH should not be effecting the demand as this statement would suggest.  What is more likely is this is a side-effect of the Pathfinding itself, something more along the lines of something I posted earlier where the buildings are dilapidating due to the number of paths in that building being "not valid" but not enough to the point where the building has abandoned.  Quoted below is that theory I had posted over a week ago:

The relevant part in this quoted post is where it discusses the part of the theory is where the game determines how to abandon a building.  Dilapidation would come into effect here because it would create a buffer zone between "normal occupancy" and "outright abandonment".


Not just the max commute time, but the ph as well...I think. I haven't observed the speed effect myself, but then Steve was doing timed tests. I've had too much else going on to do any kind of timed tests yet.

I am also still able to get quite a lot of abandonment with .003 , same testbed. It takes a bit of congestion at least, but still the network is overkill and there are plenty of alternate routes. I just upped the max commute to 30 but haven't had time to get results (yes it is likely if I up it to 60 it will stop, but I am trying to find the lower end :P ). I also set everyone to 100% fastest method. Either it will help me isolate MT vs car or it will just fubar the game ;D .

I haven't had time to try to observe the attractiveness theory, although in regards to the ph, we know it shouldn't have anything to do with it; yet it is pretty clear it seems to effect more things than it should. As far as it being the pathfinder though, changing the ph does directly affect the pathfinder, so if you think it is the pathfinder then you can't disagree with the ph.

I still think your dilapidation/abandonment theory is valid, but I don't see how this contradicts it.

Anyway, I know your post was directed to Steve, but I had to throw my 2¢ in  :P
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 08, 2009, 12:03:36 AM
I haven't had time to try to observe the attractiveness theory, although in regards to the ph, we know it shouldn't have anything to do with it; yet it is pretty clear it seems to effect more things than it should. As far as it being the pathfinder though, changing the ph does directly affect the pathfinder, so if you think it is the pathfinder then you can't disagree with the ph.

I still think your dilapidation/abandonment theory is valid, but I don't see how this contradicts it.

Anyway, I know your post was directed to Steve, but I had to throw my 2¢ in  :P

I think Steve's wording was probably misleading.  His tests seem to confirm the theory I posted last week, but the PH isn't effecting the demand (the way I would read attractiveness would in my mind be translated to demand in technical terms)... I do not think dilapidation is a mechanic of a demand related situation, but a technical response to how the game is handling the finding of "valid commuters" and "invalid commuters".

A question I would have now would be does the demand for R$ go down and the demand for R$$$ go up with the changes that occur?  If this is the case, then as a side-effect of that mechanic it would effect demand but instead R$$$ demand is rising instead of falling as Steve suggested.  But this would be due to the drop in population for R$$$ and rise in population for R$.  If the demand stays the same, the game may actually still interpret many of those buildings to be still considered R$$$ buildings even though they are dilapidated and still fill the higher wealth jobs available.

I simply dont see the direct relationship to demand that Steve has suggested.  I see a mechanic the game employs while handling "invalid traffic routes".
Title: Re: Traffic Simulator Z Development
Post by: z on November 08, 2009, 01:56:36 AM
I did not "challenge you to a duel" and I think you should stop acting that I am "dueling" with you... I am sorry you have seen this as some kind of duel....  Where it is clearly a one-sided duel and one I am not trying to participate in but collaborate in a group effort.

There is a misunderstanding here.  I do not see this as a duel, or that you are dueling with me.  What you quoted was intended to be a joke, and to lighten things up a bit, especially as I was about to drag people through a long and complex post.  The "dueling" part was crossed out; I stated, "No, that can't be right," and I proceeded to make a little fun of myself for not seeing what was really going on.  It seems to me that if I was attacking anyone in that statement, it was myself.  Between that, the various animals jumping up and down, the other animated icons, and the other jokes, I really didn't expect anyone to take that part of the post seriously.  I am sorry that you did; please simply see this as humor that did not work as intended.

Quote
  I am tired of your attitude and the way you relentlessly attack my work with impunity.

I don't understand this part.  I went over the main body of the post several times, doing my best to keep it clear of anything that might be interpreted as an attack on your work.  I changed a number of things that were slightly ambiguous for this very reason.  I threw in the "Disclaimer" which was also designed to be a little humorous, but which clearly stated that the purpose of my post was to understand properties of the simulator in general, and not to compare the worthiness of any simulators.  You had asked if the effects I had previously demonstrated with Simulator Z could be shown with Simulator A, and my tests were designed to show that.  The tests were focused on how various properties of the simulator worked; I just don't see where there was any attack.

Quote
Believe me I have been trying really hard not to fight with you and give you some respect, unfortunately I do not feel you see it, nor are you even trying to give me that same respect.

I do believe you, and I have seen it.  And I have been trying to do the same with you, and trying to stick to dealing with facts.  So please, let's accept our mutual good intentions here (which I really do believe are genuine on both sides) and try to move forward.

I have a problem with your assertion that "Higher Max Commute Time" = faster game speed.....  You have pointed out that Simulator A runs slower than other Simulators, which is true.  So, then if Maximum Commute Time is what creates this "slowness" why does Simulator A run slower than the default Simulator when Simulator A has a Max Commute Time almost 3x higher?

I haven't done any measurements on the speed of the default Simulator.  Have you, or have you seen any?

The effect of the maximum commute time on the speed is easy to verify, once you know to look for it.  Just take any city that's big enough so that the game slows down in Cheetah mode when Simulator A runs.  Time how fast the game runs.  Then change the maximum commute time to 600, and run the same test on the same city.  You should see a measurable difference.  Since the difference is connected with the pathfinding engine, it will vary exponentially with the size of the city, so you're unlikely to get the exact same results I did.  On the other hand, you should easily be able to replicate the effect whereby Simulator A runs slightly faster than Simulator Z.

Quote
Your post is interesting.  You have shown that the 0.009 value can cause abandonment in any Simulator, but still there are questions why it happens in some cities but not all.  You again have attacked me in trying to say I have missed it... but it is hard to say I miss it when I don't run into the problem.

I had realized that I hadn't fully answered this part of the question, and I was planning to address it more.  I think that what it comes down to is what you call playing style.  There are two aspects of your playing style that you have publicly described that would explain why you don't see this effect.  First, you tend to play smaller cities than the one I used in my tests, and based on the way A* works, this would make it exponentially less likely that you would see such an effect.  As I mentioned, I went through your whole testing thread, and the only place I saw evidence of this effect was in Nate's city.  But that was by far the largest city in your tests, with all other cities being under a million, as far as I could tell.  So there's a huge connection between the likelihood of this happening and the size of the city, which your tests appear to confirm.  Nate's city when we started was about the same size as my test city.

The second factor is that in your cities, you tend to mix different zone types closely together.  This not only makes paths between Sims and their jobs shorter, but it means that there tend to be a lot of short, valid paths between Sims and their jobs.  This makes the job of the pathfinder much easier.  Combine that with the fact that in smaller cities, there are less paths that need to be searched, and the result is that the pathfinder does not need such a precise setting to find correct paths reliably.

I saw this effect with the Maxis simulator when I first played the game.  On medium-sized tiles, it worked reasonably well for me.  But on large tiles, things really fell apart.  (Please note:  I am not trying to compare the Maxis simulator to Simulator A; I am just comparing this one effect.  Simulator A is obviously vastly superior to the Maxis simulator in just about every conceivable way.)

Quote
I also disagree with your assertion that the City is "less attractive" to R$$$ Sims and more attractive to R$ Sims.  The PH should not be effecting the demand as this statement would suggest.  What is more likely is this is a side-effect of the Pathfinding itself, something more along the lines of something I posted earlier where the buildings are dilapidating due to the number of paths in that building being "not valid" but not enough to the point where the building has abandoned.

I agree with your theory here; this is the only explanation I could think of for why this was happening.  But at this point it's still a theory until this mechanism is proven to be the one in operation.  Nevertheless, I believe it; I do not believe, nor did I claim, that the PH has a direct effect on demand.  The reason I stated my conclusion in terms of attractiveness is that this is the observable effect; the rest is still theory at this point, even though I think it's a good theory.

I am also still able to get quite a lot of abandonment with .003 , same testbed.

I have also been doing more tests along these lines, and the more I do, the more I think we're dealing with two different constants:  1) There's the "perfect" PH, which always produces the fastest paths.  Determining this exactly experimentally is extremely difficult, as it means calculating and comparing the travel time of hundreds, if not thousands, of paths.  We know it's somewhere near .003; as Tropod claimed that that was the number, I'm willing to go with it until proven otherwise.  2)  There's the "no abandonment" PH, which is the level that no abandonment due to commute time ever occurs because the pathfinder fails to find a valid path.  Preliminary experiments seem to show that the value of this second constant is somewhere between .002 and .0025.

I assume you are using your simulator on your testbed.  If so, try using Simulator Z and see if that makes a difference.  If you get a lot of abandonment with Simulator Z, I'd be interested in looking into this more.

I think Steve's wording was probably misleading.  His tests seem to confirm the theory I posted last week, but the PH isn't effecting the demand (the way I would read attractiveness would in my mind be translated to demand in technical terms)... I do not think dilapidation is a mechanic of a demand related situation, but a technical response to how the game is handling the finding of "valid commuters" and "invalid commuters".

Just to confirm, I agree with this interpretation, and this is what I saw as the mechanism behind the results.

Quote
A question I would have now would be does the demand for R$ go down and the demand for R$$$ go up with the changes that occur?  If this is the case, then as a side-effect of that mechanic it would effect demand but instead R$$$ demand is rising instead of falling as Steve suggested.  But this would be due to the drop in population for R$$$ and rise in population for R$.  If the demand stays the same, the game may actually still interpret many of those buildings to be still considered R$$$ buildings even though they are dilapidated and still fill the higher wealth jobs available.

I did not see any change in demand, which makes sense to me.  The jobs are still there, but the R$$$ Sims can't find them.  I would think that the reason that the R$$$ Sims are affected in this way and not the R$ Sims is that there are fewer high-wealth  jobs than their low-wealth counterparts, and therefore a lot fewer valid paths between the R$$$ Sims and their jobs.  As a result, a decrease in pathfinder efficiency would hit the high-wealth Sims before it hit the low-wealth Sims.  From my tests, it appears that a value of .009 for the PH is high enough to create this problem for the R$$$ Sims, but not high enough to create it for the R$ Sims.  This is just a theory, though.

Quote
I simply dont see the direct relationship to demand that Steve has suggested.  I see a mechanic the game employs while handling "invalid traffic routes".

I don't see a direct relationship either, and I didn't mean to imply one.  It's an indirect relationship, and at this point we don't know for sure what the intermediate steps are.  But I do agree with your conclusion.

Now, should I put together that post about Nate's city that I mentioned earlier, or not?  If everybody's made up their mind one way or another about these issues, then there wouldn't seem to be much point in doing it, especially as it would take some time to do.  But if people think it would be helpful, I would be happy to do it.  Jason, if you are interested in such a post, you could help me by furnishing the capacity numbers for the simulator used in the tests.  Otherwise, I'll use my best estimate.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 08, 2009, 02:11:53 AM
Jason, if you are interested in such a post, you could help me by furnishing the capacity numbers for the simulator used in the tests.  Otherwise, I'll use my best estimate.

I do not have exact numbers anymore....  As I have stated before the capacity numbers are very similar to those used in the Medium version +/- only a little bit within 50 to 100 in many cases.  I think if I remember back 2 years correctly the biggest change was in the MT capacities which were raised slightly from around 10,000 to where they are now.  It is very similar.

There is a misunderstanding here.  I do not see this as a duel, or that you are dueling with me.  What you quoted was intended to be a joke, and to lighten things up a bit, especially as I was about to drag people through a long and complex post.  The "dueling" part was crossed out; I stated, "No, that can't be right," and I proceeded to make a little fun of myself for not seeing what was really going on.  It seems to me that if I was attacking anyone in that statement, it was myself.  Between that, the various animals jumping up and down, the other animated icons, and the other jokes, I really didn't expect anyone to take that part of the post seriously.  I am sorry that you did; please simply see this as humor that did not work as intended.

This was a very bad joke and one out of place given our history together.


I am tired of your attitude and the way you relentlessly attack my work with impunity.

I don't understand this part.  I went over the main body of the post several times, doing my best to keep it clear of anything that might be interpreted as an attack on your work.  I changed a number of things that were slightly ambiguous for this very reason.  I threw in the "Disclaimer" which was also designed to be a little humorous, but which clearly stated that the purpose of my post was to understand properties of the simulator in general, and not to compare the worthiness of any simulators.  You had asked if the effects I had previously demonstrated with Simulator Z could be shown with Simulator A, and my tests were designed to show that.  The tests were focused on how various properties of the simulator worked; I just don't see where there was any attack.

Before I even read your post I have to comment on this...

You missed the very first line of my post... I had not read any of your post beyond your comment about "dueling".  The comment on your attitude has been a reflection of what I have felt since I've started posting again with your general posts.  But, yes there are points within your post above that I still feel you have either failed at humor or simply trying to undermine my questions.  Here is an example of what I am talking about:

So I think I have demonstrated that the same effects I have shown happening in Simulator Z can also happen in Simulator A.  But obviously, they don't happen all the time, as Jason has pointed out.  So now it's time to answer his question:  Why hasn't he seen these effects?  I have also gone through the entire testing thread he referenced, and certainly, I think that the general feeling any reader of that thread would get would be that this simulator was working quite well, was a big improvement over previous simulators, and had no major problems.  I think one summary Jason posted is also relevant:

I would agree with this completely, and in fact, this is what I have concentrated on showing in this post.  Why didn't Jason see any of this?

How would you read this if the table was turned?  It seems to me you are trying to undermine my credibility even though in a later post you point out reasons why it really hasn't been a major problem in cities shown during testing, and the fact that my own playing style avoids that problem completely, which is answering your own question.

Quote
I haven't done any measurements on the speed of the default Simulator.  Have you, or have you seen any?

The effect of the maximum commute time on the speed is easy to verify, once you know to look for it.  Just take any city that's big enough so that the game slows down in Cheetah mode when Simulator A runs.  Time how fast the game runs.  Then change the maximum commute time to 600, and run the same test on the same city.  You should see a measurable difference.  Since the difference is connected with the pathfinding engine, it will vary exponentially with the size of the city, so you're unlikely to get the exact same results I did.  On the other hand, you should easily be able to replicate the effect whereby Simulator A runs slightly faster than Simulator Z.

I had a number of people question why their game ran slower after Simulator A was installed.  In a thread back in ST, long ago....  I don't have any test results on my own because I thought at the time it was related to the PH being lower.  But, I do remember the "slowdown" and I had been using the default Simulator prior to creating Simulator A.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on November 08, 2009, 04:20:43 AM
I would like to second catty's suggestion in an earlier post above, for some 'neutral' testers to run tests on various cities found in the provided link. To the extent of my free time (which is not great these days and will get worse in the coming weeks because I will be moving) I would be pleased participate to such testing. Conditions of each test (city, simulator version/variant, duration, pictures to produce, etc) should be defined in detail to make sure that the tests produce valid and comparable results.

At any rate I wish that the discussions taking place in this thread - and in the related thread opened by ldog - remain as objective and factual as possible. They are invaluable as research and information about a particularly fascinating area of the game, and they allow players such as myself to learn a lot, to improve our playing styles and to try out new ways of building and interconnecting our cities. Please let's all try to remain dispassionate and zen about it.
Title: Re: Traffic Simulator Z Development
Post by: pierreh on November 08, 2009, 04:24:44 AM
This is the report about the results of my second comparative tests between the Standard and the Euro Simulators, High variant. However, first I would ask Steve to open a new thread dedicated to the Euro variant of the Z Simulator and move the posts that pertain to it to that new thread, including this one, so that the discussion about the Euro variant can be separated from the much larger discussion taking place here.

The second test city is built on a large tile, on both shores of a wide river. There is still some room for expansion on the tile. The population at the start of the tests is very near 759k Sims.
The city has buses, a subway network that started to be developed when the city reached a population of 200k, and a railway network with two main stations (one on each side of the river) and some suburban stations. Once the basic subway network had been established, its development followed closely that of the city and in some cases anticipated it: when zoning new areas of residential or commercial, subway lines and stations were laid out right from the start, or new stations were opened on existing lines, sometimes with partial rerouting of some sections of tunnel. Bus stops are always present right from the start of any new zoning area, whether R, C, or I.
In many areas of the city the buses play a feeder role to the subway (and also to the railway); this can be observed by looking at various route queries.

Both tests were run for 10 years. The population increased moderately during the tests:
after 10 years with Standard High Simulator: 768k
after 10 years with Euro Hiigh Simulator: 770k

Each pair of pictures below shows first the Standard results then the Euro results.

Travel Time Graph

(http://img7.hostingpics.net/pics/806894Hermone_Trajets_Std.jpg) (http://www.hostingpics.net/viewer.php?id=806894Hermone_Trajets_Std.jpg)

(http://img7.hostingpics.net/pics/714141Hermone_Trajets_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=714141Hermone_Trajets_Euro.jpg)

Car volume

(http://img7.hostingpics.net/pics/917618Hermone_Cars_Std.jpg) (http://www.hostingpics.net/viewer.php?id=917618Hermone_Cars_Std.jpg)

(http://img7.hostingpics.net/pics/572292Hermone_Cars_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=572292Hermone_Cars_Euro.jpg)

Bus volume

(http://img7.hostingpics.net/pics/874283Hermone_Bus_Std.jpg) (http://www.hostingpics.net/viewer.php?id=874283Hermone_Bus_Std.jpg)

(http://img7.hostingpics.net/pics/205889Hermone_Bus_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=205889Hermone_Bus_Euro.jpg)

Subway volume

(http://img7.hostingpics.net/pics/597326Hermone_Sub_Std.jpg) (http://www.hostingpics.net/viewer.php?id=597326Hermone_Sub_Std.jpg)

(http://img7.hostingpics.net/pics/418927Hermone_Sub_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=418927Hermone_Sub_Euro.jpg)

Traffic densities; car, bus, subway and passenger trains

(http://img7.hostingpics.net/pics/928236Hermone_Densite_Std.jpg) (http://www.hostingpics.net/viewer.php?id=928236Hermone_Densite_Std.jpg)

(http://img7.hostingpics.net/pics/959510Hermone_Densite_Euro.jpg) (http://www.hostingpics.net/viewer.php?id=959510Hermone_Densite_Euro.jpg)


In the graphs, the flat lines during the first 18 months show the values produced by the standard Z High Simulator prior to the start of the test. The first run of the Simulator is about 18 months after the start of the test, and from that point on the graphs show variations.

Once again, not a lot of difference can be seen between the results produced by each variant of the Z High simulator. For buses, as mentioned above, the fact that there are a lot of short bus trips between the starting point and the next subway station, and the other subway station and the destination (feeder/distributor role of the buses) may explain the similarities observed between both tests. Subway volumes on the various segments of the network are a bit different between both tests but the global usage densities are quite similar.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 08, 2009, 07:36:37 AM





I had realized that I hadn't fully answered this part of the question, and I was planning to address it more.  I think that what it comes down to is what you call playing style.  There are two aspects of your playing style that you have publicly described that would explain why you don't see this effect.  First, you tend to play smaller cities than the one I used in my tests, and based on the way A* works, this would make it exponentially less likely that you would see such an effect.  As I mentioned, I went through your whole testing thread, and the only place I saw evidence of this effect was in Nate's city.  But that was by far the largest city in your tests, with all other cities being under a million, as far as I could tell.  So there's a huge connection between the likelihood of this happening and the size of the city, which your tests appear to confirm.  Nate's city when we started was about the same size as my test city.

The second factor is that in your cities, you tend to mix different zone types closely together.  This not only makes paths between Sims and their jobs shorter, but it means that there tend to be a lot of short, valid paths between Sims and their jobs.  This makes the job of the pathfinder much easier.  Combine that with the fact that in smaller cities, there are less paths that need to be searched, and the result is that the pathfinder does not need such a precise setting to find correct paths reliably.

I saw this effect with the Maxis simulator when I first played the game.  On medium-sized tiles, it worked reasonably well for me.  But on large tiles, things really fell apart.  (Please note:  I am not trying to compare the Maxis simulator to Simulator A; I am just comparing this one effect.  Simulator A is obviously vastly superior to the Maxis simulator in just about every conceivable way.)




    I had switched traffic sims from traffic sim B (hard) to traffic sim Z (low)..  So hope i can contribute
something worthwhile to the discussion..  Regrettably , i dont have any pics to confirm any of this but I'm
quite sure of my recollection as to why i changed traffic sims to Z (low)..

   At the time of the traffic Sim i had cities which were played all on large city tiles.. The largest of these cities
which as i recall, was right around a million sims, i began to experience abandonment due to commute times..
Trying some different strategies to deal with this issue, I eventually found the best solution was to mix the zones
as Steve was suggesting in the above post, and I found this solved my problem to a large degree , although
i still had spotty abandonment here and there.. it was also about this time steve  was putting the final touches
to sim Z, and i thought i would change traffic sims and give sim Z a try.. Once I changed all the commute
issues vanished for me.. , and ive been using sim Z without any further abandonment issues since..
( city is now approaching 2 million in population )..

    So anyways since there hasn't been nearly as much discussion on sim B in the various traffic sims I decided
to have a look at traffic sim B using the reader.. I found out the sim B hard i was using actually had a PH 8 times higher
value than sim Z does.. (0.025) as compared to .003..  So I just assumed the improvement i experienced to be
caused by a combination of (all) the changes Z made with sim Z.. (maximum commute times being longer), ect;
So I think its possible you can see changes based on just one factor sometimes like different (ph settings),
but i feel its more likely it often involves multiple factors , only because this area of the game is quite complex.
i do feel it does seem to take a few factors brought together , before the averge player (like myself) would
notice any worthwhile difference between the 3 traffic sims  (A, B or Z).. in my case..

     1.) .. city tile size (large) .
     2.) .. large city population  (over a million sims) .
     3.)... zone placed far apart.. ( fairly longer distances between where the sims live and have to commute
                                              .. to and from work ) .

over the past several months i have used and tested ( for steve).. all 3 of the traffic sims A, B. and Z..
and my position always was that any of the 3 traffic sims were excellent and high quality traffic sims for the
majority of players..  And i still recall back in the old days using that original maxis pathfinding engine, and would
feel very confident that any of the 3 traffic sims be it  (A, B or Z) are vastly superior to original traffic simulator
 in many wayshave already been discussed and documented.. yet i hope i have contributed something to this 
discussion in a small way through my experiences playing all of them..

Thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: z on November 08, 2009, 05:23:51 PM
I found out the sim B hard i was using actually had a lower PH value than sim Z does.. (0.025) as compared to .03.

A quick but important correction:  Simulator B actually has a PH eight times higher than Simulator Z's:  .025 vs. .003.  It's easy to miss that extra zero.  But this has major implications for what follows in Brian's post.

More on some other topics later...
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 08, 2009, 06:04:20 PM
I have also been doing more tests along these lines, and the more I do, the more I think we're dealing with two different constants:  1) There's the "perfect" PH, which always produces the fastest paths.  Determining this exactly experimentally is extremely difficult, as it means calculating and comparing the travel time of hundreds, if not thousands, of paths.  We know it's somewhere near .003; as Tropod claimed that that was the number, I'm willing to go with it until proven otherwise.  2)  There's the "no abandonment" PH, which is the level that no abandonment due to commute time ever occurs because the pathfinder fails to find a valid path.  Preliminary experiments seem to show that the value of this second constant is somewhere between .002 and .0025.

I would reach a different conclusion.
Some of us around here are really stuck on "perfect ph = .003" :P
At any rate, the experimentation is providing new information, which I think we can all agree is a good thing.

I assume you are using your simulator on your testbed.  If so, try using Simulator Z and see if that makes a difference.  If you get a lot of abandonment with Simulator Z, I'd be interested in looking into this more.

Yup. You guys keep plugging your sims. I get it, I get it. Part of why I am experimenting with my own was cause I wanted to avoid this whole raging "coke vs pepsi" debate. If I used A or Z, then everything would be seen as biased, and then I'd have to do run every experiment twice or you guys would never be happy. I'm just trying to get to the bottom of how the blasted thing really works.  I have appreciated the valuable insight I get from BOTH of you. Now I didn't go and pick B as "the third neutral candidate"...I decided to do my own thing. I looked at B after and noticed how similar it was, but then that was no shocker. Mott's theories were a big influence. I suspect they were for you and Jason as well and you guys probably started with something similar and went from there.

At this point I am pretty sure with my super craptastic building methods I can make any simulator cry uncle :P

Seriously though, if I jacked my commute time up to 600 in mine even the abandonment would likely go away. I am still not overly concerned about the abandonment at the moment; I was just adding that my findings tend to confirm yours, even when they weren't the thing I was trying to find lol. Likely it will still come down to a design choice at some point on when and how much abandonment is allowable from the simulator to as Jason says "preserve some level of difficulty".

Just making the ph really low and the max commute time very high is still not the answer for all occassions. Besides abandonment, what other penalty can the traffic simulator impose on us for bad citybuilding decisions? Chaos of cars spam? I admit that is annoying but not enough. If we could fully congest all available networks to red all the time but everything still worked then as long as you provide a valid route you can do whatever you want. Of course there could be other more tangible effects but I can't think of them at the moment (which doesn't mean I think I have been exhaustive; I am still asking the question...I don't feel I have answered it)
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 08, 2009, 07:22:35 PM
A quick but important correction:  Simulator B actually has a PH eight times higher than Simulator Z's:  .025 vs. .003.  It's easy to miss that extra zero.  But this has major implications for what follows in Brian's post.

More on some other topics later...


Thanks, for that important correction Steve...

          Both the rest of my post above , and your recent findings on the testing of the different PH values..
Make a lot more sense to me now.. I apologize to those I may have caused additional confusion to, on account of
my oversight .

Brian
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 08, 2009, 11:04:32 PM
Yup. You guys keep plugging your sims. I get it, I get it. Part of why I am experimenting with my own was cause I wanted to avoid this whole raging "coke vs pepsi" debate. If I used A or Z, then everything would be seen as biased, and then I'd have to do run every experiment twice or you guys would never be happy. I'm just trying to get to the bottom of how the blasted thing really works.  I have appreciated the valuable insight I get from BOTH of you. Now I didn't go and pick B as "the third neutral candidate"...I decided to do my own thing. I looked at B after and noticed how similar it was, but then that was no shocker. Mott's theories were a big influence. I suspect they were for you and Jason as well and you guys probably started with something similar and went from there.

I'm in the same boat. I've learned enough from Jason, and by tinkering under the hood, to be able to personalize the traffic sim to suit my particular needs, and my playing style. It may just be a jacked up version of A, but I knew the research involved in it, and had tested it thoroughly, along with any changes I've made.

I've always been willing to test anything, but for me to actually be able to give Barby my thumbs up on any mod going to the LEX, or to recommend it to someone else... that's gonna take some serious convincing.

Quote
At this point I am pretty sure with my super craptastic building methods I can make any simulator cry uncle :P

I can make em scream... But this comes in handy when people want testers for their latest simulator, huh?

Quote
Seriously though, if I jacked my commute time up to 600 in mine even the abandonment would likely go away. I am still not overly concerned about the abandonment at the moment; I was just adding that my findings tend to confirm yours, even when they weren't the thing I was trying to find lol. Likely it will still come down to a design choice at some point on when and how much abandonment is allowable from the simulator to as Jason says "preserve some level of difficulty".

If I increase my commute time any at all, my abandonment issues go away almost instantly. Why? Because now my Sims can travel 3 tiles over to find work... and that always ends up in an unplayable region for me. It may have been ok for me to have to travel an hour or more to work, in real life, but the problems it can create in SC4 are just not worth it to me. And as there is no truly regional traffic simulator (unless I've missed something?), it would be my guess that the game isn't designed for extended commutes between tiles.

Quote
Just making the ph really low and the max commute time very high is still not the answer for all occassions. Besides abandonment, what other penalty can the traffic simulator impose on us for bad citybuilding decisions? Chaos of cars spam? I admit that is annoying but not enough. If we could fully congest all available networks to red all the time but everything still worked then as long as you provide a valid route you can do whatever you want. Of course there could be other more tangible effects but I can't think of them at the moment (which doesn't mean I think I have been exhaustive; I am still asking the question...I don't feel I have answered it)

It seems like Jason and I tested this out too... in a thread at Simtropolis. By providing ped malls as the ONLY path from residential zones to any jobs, we proved that Sims will do everything they can to get to work, even if it means going beyond the commute time set up in the traffic sim, as long as there is a valid route provided. (I don't have a link... Jason might?)
Title: Re: Traffic Simulator Z Development
Post by: z on November 09, 2009, 04:03:43 AM
So many posts to respond to.  I'll just start here, get as far as I can, and continue tomorrow.

[Lenny quotes my conclusion that there are two different pathfinding constants.]
I would reach a different conclusion.
Some of us around here are really stuck on "perfect ph = .003" :P
At any rate, the experimentation is providing new information, which I think we can all agree is a good thing.

Here's some more information, which is part of what led to my conclusion.  When I take the standard Simulator Z and drop the PH to .0025, abandonment doesn't decrease at all.  In fact, it's the same level that it was at .0025 with my older version of Simulator Z, even though that version showed more abandonment at .003.  ()what()  This certainly isn't proof, but it does make me think that there are two different mechanisms going on here.

The .003 number for the perfect PH is just a hypothesis, but it seems a pretty good one, based on the evidence.  I also put a lot of weight in what the7trumpets and Tropod say.  If you don't think .003 is the right number, all you have to do is find one path that's not the fastest path, in any city that's been running with that PH for at least several decades.

From me:
Quote
I assume you are using your simulator on your testbed.  If so, try using Simulator Z and see if that makes a difference.  If you get a lot of abandonment with Simulator Z, I'd be interested in looking into this more.
From Lenny:
Quote
Yup. You guys keep plugging your sims. I get it, I get it. Part of why I am experimenting with my own was cause I wanted to avoid this whole raging "coke vs pepsi" debate. If I used A or Z, then everything would be seen as biased, and then I'd have to do run every experiment twice or you guys would never be happy.

I think you have missed my point here.  I am not trying to "plug" my simulator; I just want to see if what you have found is a general principle, in which case I should look at it, or it's just a property of your simulator, in which case it's not my concern.  As I have shown with my example of the older version of Simulator Z, there are other factors beside maximum commute time and PH that affect the amount of abandonment due to commute time.  If you want the claims in your post to be more than mere speculation, you need to test Simulator Z.  You may be right about your conclusion; I don't know, since I haven't played your city.  But you'll never really know without testing.

Quote
At this point I am pretty sure with my super craptastic building methods I can make any simulator cry uncle :P

As Jason said to me, "Prove it."  I thought his request was reasonable, and I did exactly what he said.  What about you?  ;)

Quote
Seriously though, if I jacked my commute time up to 600 in mine even the abandonment would likely go away.

It seems to me that you are getting deeper and deeper into mere speculation.  Let's do a real test.  We'll take Simulator Z (Low), and get rid of that 600 maximum commute time.  We could use Simulator A's value of 17, but I always like to test the extremes, as they often give the most interesting results.  So I'll use the original Maxis value of 6 for the maximum commute time, with 4 for the mass transit maximum commute.  That gives the Sims all of three minutes to get from their homes to their jobs.  I'll admit, I'm not expecting the results to be pretty when I start this test.

[EDIT:  I later reran these test with a maximum commute time of 4, giving the Sims a total of two minutes to get from their homes to their jobs.  There was a little bigger bump in the commute time graph during the transition, but all the other results were identical to that of this test.]

We start with the same city, same time - January, 433.  I run the simulator for eleven years and take a look around.  Very interesting!  I took a picture, but there's no need to show it, because after running the simulator for another 20 years, the picture is identical.  Here's what my city looks like after running with a maximum commute time of 6 for 31 years:

(http://img130.imageshack.us/img130/6619/mnss2.jpg)

There is no abandonment anywhere in this picture.  There's not even any additional downgrading.  The only two downgraded buildings in this picture have been downgraded since before the test began.  Would anyone have predicted this?  I didn't.

These results were so surprising to me that I had to question them.  Again, was I really using the proper simulator?  How could I tell?  Well, normally I don't pay any attention to the commute time graph, since Simulator Z normally has effectively unlimited commute time, but this time that graph should show something.  If the simulator really did rearrange all the Sims' routes so that they could reach their jobs in three minutes, you would really expect to see a significant change in the commute time graph.  Let's see:

(http://img39.imageshack.us/img39/3450/mnss3.jpg)

This certainly is about what we would expect to see.  Commute time had plenty of room to fluctuate under the standard simulator.  But it starts dropping sharply at the transition, and levels out about 60% down from its peak.  It eventually settles a line that is almost flat; I would expect that the average commute time is very close to the maximum here.  And although I always stress that the numbers in the commute time graph cannot be made perfectly accurate, they're not that far off here; maximum commute time is 6, and the line levels out around 7.5.

OK, to me that's excellent evidence that we're using the right simulator.  There's more evidence coming later.  But first, let's check in with our old friend, the Pop & Jobs Graph:

(http://img39.imageshack.us/img39/1040/mnss4.jpg)

This is another interesting graph.  There's certainly no divergence here - there shouldn't be if there's no abandonment or downgrading in the city.  Instead, the trends that were in place before the switch simply continue.  The R$$$ population continues to increase, as it has been doing since I introduced Simulator Z v1.2, although the increase is gradually leveling off.  Meanwhile, the R$$ population is decreasing somewhat faster than the R$$$ is increasing.  Total population has decreased slightly.  This is just the opposite of what we had seen before; in this case, as I verified by looking around the city, R$$$ buildings that had been downgraded to R$$ for centuries are slowly being upgraded to R$$$.  Other R$$ buildings are being replaced with R$$$ buildings.  How is the simulator doing this when the maximum commute time has been cut by 99%?  The Traffic Volume Graph gives us another clue:

(http://img198.imageshack.us/img198/9608/mnss5.jpg)

The Sims are moving out of their cars and taking the subway more.  (The downward spikes are artifacts that occur when I save the game).  This movement to the subway makes sense, as the subway is much faster than cars.  Even so, it's not a very big difference, and it's especially impressive in terms of pathfinder ability when you remember that subway speeds were reduced by 30% in Simulator Z v1.2, to 105 kph.  Car speeds were left unchanged at 50 kph.

So everything is consistent here; I'm just really surprised at how well the pathfinder is doing.  If .003 isn't the perfect PH, then it's awfully close.  What do you think, Lenny?

Finally, here's the congestion minimap for the city:

(http://img130.imageshack.us/img130/4746/mnss6.jpg)

All in all, it looks pretty reasonable.  My conclusion:  The effect of the maximum commute time in the game is highly overrated.  The PH appears to be the most important parameter by far in the traffic simulator.

Quote
I am still not overly concerned about the abandonment at the moment; I was just adding that my findings tend to confirm yours, even when they weren't the thing I was trying to find lol. Likely it will still come down to a design choice at some point on when and how much abandonment is allowable from the simulator to as Jason says "preserve some level of difficulty".

Just making the ph really low and the max commute time very high is still not the answer for all occassions. Besides abandonment, what other penalty can the traffic simulator impose on us for bad citybuilding decisions? Chaos of cars spam? I admit that is annoying but not enough.

OK, how about an increase in noise that makes residential areas less desirable, an increase in pollution, and a decrease of up to 14 points in the local Mayor Rating?  These all occur when your congestion gets too bad, and they all have side effects themselves.  As you may remember, Shadow Assassin found that the lower Mayor Rating was a contributing cause to riots in his city.  If your congestion is widespread, this can have a significant effect on your global Mayor Rating, which affects which rewards you can get.  To quote the Prima Guide regarding the awards:

Quote
In addition... they improve your city in myriad other ways (enhancing desirability, boosting EQ or HQ, further increasing Mayor Rating, to name a few).

Note the last point.  This means that bad traffic can eventually cost you a lot more than 14 points in your Mayor Rating, ending up having a very major effect on the game, even with no abandonment due to commute time.  And abandonment due to demand may still happen, of course, and if you look at the above quote, you can see how bad traffic can start a cycle than can result in exactly that.

If I increase my commute time any at all, my abandonment issues go away almost instantly. Why? Because now my Sims can travel 3 tiles over to find work... and that always ends up in an unplayable region for me. It may have been ok for me to have to travel an hour or more to work, in real life, but the problems it can create in SC4 are just not worth it to me. And as there is no truly regional traffic simulator (unless I've missed something?), it would be my guess that the game isn't designed for extended commutes between tiles.

I agree - the game wasn't designed for extended commutes between tiles.  That doesn't mean that we can't make it work, though.  One of the main original design goals of Simulator Z was to provide what you call a truly regional traffic simulator.  That's what the Ultra capacity level is really for - it's for when you have Sims commuting not only in your city, but coming and going from various surrounding cities as well, thus being counted as commuters in all of them.  But as you indicate, the limitations in the game to doing this are serious, and they aren't something that the traffic simulator can completely overcome on its own.  However, with CAM 2.0, I think we will finally have a platform where effective intercity commuting over many tiles can actually work well.  The ESURE project, providing express subways that allow you to control to some extent where the Sims commute, will also help in this area.

I'll get to more posts tomorrow...
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 09, 2009, 05:33:12 AM

[Lenny quotes my conclusion that there are two different pathfinding constants.]
Here's some more information, which is part of what led to my conclusion.  When I take the standard Simulator Z and drop the PH to .0025, abandonment doesn't decrease at all.  In fact, it's the same level that it was at .0025 with my older version of Simulator Z, even though that version showed more abandonment at .003.  ()what()  This certainly isn't proof, but it does make me think that there are two different mechanisms going on here.




   Steve ,
.. on the second .0025.. I assume you meant to type .003 right ?
In fact, it's the same level that it was at .xxxx

Thanks, brian
Title: Re: Traffic Simulator Z Development
Post by: z on November 09, 2009, 05:44:12 AM
No, it's correct as it reads.  I'm comparing two versions of Simulator Z here.  The story began back in Lenny's thread somewhere, which may make it a little confusing.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 09, 2009, 06:05:34 AM
No, it's correct as it reads.  I'm comparing two versions of Simulator Z here.  The story began back in Lenny's thread somewhere, which may make it a little confusing.

   Ok, thanks for clearing that up Steve.. I never knew the older Z had actually a lower PH , that's quite
interesting.. Although I think i was more surprised when I found out Sim B had a PH actually 8 times higher
than our current sim Z.. I mean i expected it to be higher , but perhaps not to that degree,,

  However, although it seems  like quite a bit (8 X), I take it the actual differences the average gamer sees from
the much high PH setting alone would not be quite as dramatic... and it takes all the different property changes
between sim Z and the other 2 traffic sims,  (A and B ) to make a noteworthy difference ?

Thanks, brian
Title: Re: Traffic Simulator Z Development
Post by: z on November 09, 2009, 06:22:58 AM
   Ok, thanks for clearing that up Steve.. I never knew the older Z had actually a lower PH

Actually, it didn't.  I just gave it one for a particular test.

Quote
  However, although it seems  like quite a bit (8 X), I take it the actual differences the average gamer sees from
the much high PH setting alone would not be quite as dramatic... and it takes all the different property changes
between sim Z and the other 2 traffic sims,  (A and B ) to make a noteworthy difference ?

Simulator B has a longer maximum commute time:  24 minutes, vs. 17 for Simulator A.  This helps make up for the difference in PH, at least to some extent.  Although I just went through a long test showing how maximum commute time was overrated, it becomes more and more important as the PH rises.

As a postscript to my test, I think it's important to ask, How reasonable are the results I got from a theoretical point of view?  Let's assume that the pathfinder, which appears to be very smart here, put the Sims with the longest commute on subways.  The time in minutes required to cross a single square is given by the formula .96/speed, where speed in this case is 105 kph.  Therefore, traveling by subway, the time required to cross a single square is .009 minutes.  So in a single minute, a subway can cross 111 squares; in three minutes, the maximum one-way commute, it can cross 333 squares.  Since a large tile is only 256 squares long, we seem to have met the reasonableness criterion.  Of course, this doesn't give the Sims time for leisurely walks to the station.

Just for fun, I tried reducing the maximum commute time from 6 to 4 - that's two minutes one way.  Early results seemed to indicate that the game was able to handle that, but it crashed after less than an hour.  I can't say that I blame it...  :D
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 09, 2009, 11:05:36 AM
[Lenny quotes my conclusion that there are two different pathfinding constants.]
Here's some more information, which is part of what led to my conclusion.  When I take the standard Simulator Z and drop the PH to .0025, abandonment doesn't decrease at all.  In fact, it's the same level that it was at .0025 with my older version of Simulator Z, even though that version showed more abandonment at .003.  ()what()  This certainly isn't proof, but it does make me think that there are two different mechanisms going on here.

The .003 number for the perfect PH is just a hypothesis, but it seems a pretty good one, based on the evidence.  I also put a lot of weight in what the7trumpets and Tropod say.  If you don't think .003 is the right number, all you have to do is find one path that's not the fastest path, in any city that's been running with that PH for at least several decades.

I am of course poking a little fun but if lowering the ph further changes performance then that would tend to indicate to me the perfect ph is indeed lower.
Trying to find a path that isn't the shortest would be like trying to find a needle in a haystack. Like I said early on about testing methods; one would have to count out every tile in a given route, modify it by congestion effects, figure out how long it actually took, and then start doing the same for all the alternate paths.

From me:From Lenny:
I think you have missed my point here.  I am not trying to "plug" my simulator; I just want to see if what you have found is a general principle, in which case I should look at it, or it's just a property of your simulator, in which case it's not my concern.  As I have shown with my example of the older version of Simulator Z, there are other factors beside maximum commute time and PH that affect the amount of abandonment due to commute time.  If you want the claims in your post to be more than mere speculation, you need to test Simulator Z.  You may be right about your conclusion; I don't know, since I haven't played your city.  But you'll never really know without testing.

As Jason said to me, "Prove it."  I thought his request was reasonable, and I did exactly what he said.  What about you?  ;)

I still don't understand what it has to do with Simulator Z. Jason asked you to prove it because you were making comparisons between A & Z.
I thought it was clear I was joking when I was bragging about being able to break any sim.
Newsflash, it isn't possible in a pretty vanilla game without the CAM to get a population to the kind of levels most of y'all consider routine.
Especially when you use at most about 60% of a large tile. As I've maintained since the begining, Z is too large scale a simulator for my use.
It is pretty pointless for me to run any tests using Z in any capacity. My own sim right now, I dropped the caps back to defaults because I couldn't get enough traffic.
I find the default simulator with better pathfinding and longer commute, cvs and intersection tweaks can handle things pretty well in this situation. I need to scale it back even further to maintain some challenge level.

It seems to me that you are getting deeper and deeper into mere speculation.  Let's do a real test.  We'll take Simulator Z (Low), and get rid of that 600 maximum commute time.  We could use Simulator A's value of 17, but I always like to test the extremes, as they often give the most interesting results.  So I'll use the original Maxis value of 6 for the maximum commute time, with 4 for the mass transit maximum commute.  That gives the Sims all of three minutes to get from their homes to their jobs.  I'll admit, I'm not expecting the results to be pretty when I start this test.

We start with the same city, same time - January, 433.  I run the simulator for eleven years and take a look around.  Very interesting!  I took a picture, but there's no need to show it, because after running the simulator for another 20 years, the picture is identical.  Here's what my city looks like after running with a maximum commute time of 6 for 31 years:

All in all, it looks pretty reasonable.  My conclusion:  The effect of the maximum commute time in the game is highly overrated.  The PH appears to be the most important parameter by far in the traffic simulator.

I shortened the above. A very interesting test. Which of course pushes me even deeper into mere speculation.
Because the other day you "proved" that the max commute time was much more important than thought.
Today you just "proved" that it isn't.
The more testing I do, the more confusing my results as well.

OK, how about an increase in noise that makes residential areas less desirable, an increase in pollution, and a decrease of up to 14 points in the local Mayor Rating?  These all occur when your congestion gets too bad, and they all have side effects themselves.  As you may remember, Shadow Assassin found that the lower Mayor Rating was a contributing cause to riots in his city.  If your congestion is widespread, this can have a significant effect on your global Mayor Rating, which affects which rewards you can get.  To quote the Prima Guide regarding the awards:

Note the last point.  This means that bad traffic can eventually cost you a lot more than 14 points in your Mayor Rating, ending up having a very major effect on the game, even with no abandonment due to commute time.  And abandonment due to demand may still happen, of course, and if you look at the above quote, you can see how bad traffic can start a cycle than can result in exactly that.

Thanks.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 09, 2009, 12:03:15 PM
As Jason said to me, "Prove it."  I thought his request was reasonable, and I did exactly what he said.  What about you? 

You can't make claims saying something is better and not proving it.  And I did not say "Prove it.", I was not an a-- about it like it seems you are trying to make it seem with this quote.  I said:

There are plenty of people who have said that Simulator A with its value of .009 produces too much abandonment, and if you look through the threads, you will find them.  Here's just one sample quote, from sumwonyuno:

I would like you to proove this...  I have not had any problems what-so-ever with abandonment in my cities due to the PH being higher than yours.  If you are so confident that the PH causes abandonment, proove it with Simulator Z and raise the value to 0.009 and show me the abandonment.  Abandonment is not caused by one simple factor, it is caused by many, mostly Commute Time and Congestion in your City.  And if you want to do this test there is absolutely no way you can compare Simulator A and Z you must do it with one or the other.

Obviously since I am having trouble getting abandonment in my Cities with Simulator A I cannot run this test since I am already at such a low Commute Time and high PH compared to Simulator Z.  All I can say is I cannot reproduce your abandonment issues with a "Better Pathfinding" instead of "Perfect Pathfinding".

You made a claim that others had abandonment in Simulator A which you claimed came from a higher PH.  I do not have this problem, and have not seen it in my cities and know others with "healthy" cities as well with the 0.009 PH.  You made this claim with absolutely no content or even anything to suggest this could be a problem and you used a 3rd party as the claimant who then refuted your use of his/her name as an example.  So, yes I have every right to say "Prove it." like an a--, but I was trying to be nice about it and explained why I have trouble believing that claim.

So now, you have shown that it does exist as a problem.  But you have not shown anything that can provide an explanation of why it happens in one City but not another considering there are many people who have "healthy" cities using Simulator A.

Your flat out claim seems to have some faults in it at least at this point.  And you were very pre-mature in making that claim, it would serve much better if you stopped doing things like that.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 09, 2009, 03:36:59 PM
well, I do have abandonment because of commute time, in my CAM cities, even in the early stages (about 40k to 50k). This occurs not matter what simulator I use (both 3 at high capacity though, and even at "ultra" capacity in the case of sim z). Judging which sim has the "worse" is clearly too subjective at these pop levels. Of course, I did verify that there was no other problems like desirability, crime, demand, etc...

Thinking about all this discussion, a question popped up in my mind: "could this problem come from a conflict between simcity_1.dat and the simulator dat, as it is the case with the CAM (about workforce doubling)?"
Has anybody tried to merge simulator with simcity_1.dat with datpaker (or to modify directly simcity_1.dat...)?
Title: Re: Traffic Simulator Z Development
Post by: z on November 09, 2009, 04:12:25 PM
I am of course poking a little fun but if lowering the ph further changes performance then that would tend to indicate to me the perfect ph is indeed lower.

I understand; I just wanted to toss a little more data your way.

Quote
Trying to find a path that isn't the shortest would be like trying to find a needle in a haystack. Like I said early on about testing methods; one would have to count out every tile in a given route, modify it by congestion effects, figure out how long it actually took, and then start doing the same for all the alternate paths.

I agree completely.  That's a big reason why I'm not about to do this experiment.

Quote
I still don't understand what it has to do with Simulator Z. Jason asked you to prove it because you were making comparisons between A & Z.

It's not Simulator Z as such, but the way the various parameters are tuned in it.  I was basically saying that your statements about simulators in general conflicted with my experience with Simulator Z, and since you made them without testing Simulator Z, their validity seemed questionable.  The obvious way to resolve this would be to test Simulator Z.

Quote
I thought it was clear I was joking when I was bragging about being able to break any sim.

Well yes, I did see the smiley at the end of the sentence, but why was the statement made in the first place?  I for one would be very interested if you could break Simulator Z, and I'm sure there are others out there who would also be interested.  I should also add that my interest in such a test would be to show me where the simulator could be improved, as it is still a work in progress.  I'm not claiming that it's unbreakable, but if someone can break it, I'd like to know how they do it.

Quote
Newsflash, it isn't possible in a pretty vanilla game without the CAM to get a population to the kind of levels most of y'all consider routine.

I agree, having played large tiles in a vanilla game for far too long.  But it seems that a major purpose of this whole site is to develop content that goes beyond the vanilla game, which is why these issues are relevant.

Quote
It is pretty pointless for me to run any tests using Z in any capacity. My own sim right now, I dropped the caps back to defaults because I couldn't get enough traffic.
I find the default simulator with better pathfinding and longer commute, cvs and intersection tweaks can handle things pretty well in this situation. I need to scale it back even further to maintain some challenge level.

I don't see how this follows.  You were saying earlier that you were getting a fair amount of abandonment with a PH of .003.  I would suggest testing Simulator Z Classic then.  It still has the Simulator Z core, but with the capacity levels of the original simulator.  I'm not suggesting that you use it as your simulator; you obviously want to build your own, and that's fine with me.  But there's no reason you can't do the tests to back up your statements.

Quote
I shortened the above. A very interesting test. Which of course pushes me even deeper into mere speculation.
Because the other day you "proved" that the max commute time was much more important than thought.
Today you just "proved" that it isn't.

Jason mentioned a similar point.  The tests do not provide contradictory results, however, my summary of them could have been clearer.  So let me summarize the two tests together in a way that's not contradictory:

The maximum commute time is the biggest factor by far in determining how fast the game runs.  However, when it comes to actual effects on game play, it has much less significance than previously thought; the value of the PH is much more significant in this case.

To me, that statement seems both internally consistent and consistent with both sets of test results.  Do you disagree?

You can't make claims saying something is better and not proving it.  And I did not say "Prove it.", I was not an a-- about it like it seems you are trying to make it seem with this quote.

I was doing this from memory and made the mistake you point out.  I apologize.  To me, the statements said essentially the same thing, and I emphasized that I thought it was a reasonable request.

Quote
So now, you have shown that it does exist as a problem.  But you have not shown anything that can provide an explanation of why it happens in one City but not another considering there are many people who have "healthy" cities using Simulator A.

I gave you an explanation in a recent post.  Do you disagree with that explanation?  If so, where?

From what I can tell, a majority of Simulator A users do not have this problem.  But I have heard from many who do, and for those who do have it, it can be serious.  As the very existence of this problem outside my cities is being called into question, perhaps it is time for me to gather together the quotes I had mentioned earlier.  This would at least have the effect of showing that my experience is shared by many others, something that I gather you don't believe at this point.  In some ways, the quotes are better than tests, because you don't know how often the test situations occur in actual games.  The quotes are from people who actually play the game and encounter this situation.

well, I do have abandonment because of commute time, in my CAM cities, even in the early stages (about 40k to 50k). This occurs not matter what simulator I use (both 3 at high capacity though, and even at "ultra" capacity in the case of sim z). Judging which sim has the "worse" is clearly too subjective at these pop levels. Of course, I did verify that there was no other problems like desirability, crime, demand, etc...

This definitely should not happen with Simulator Z if the city is built well.  What types of buildings are abandoning (i.e., R$, R$$, or R$$$)?  Could you please post a picture of your RCI Demand Graph, your Pop & Jobs graph, and your Traffic Congestion View minimap?  Also, how big is your abandonment problem?

Quote
Thinking about all this discussion, a question popped up in my mind: "could this problem come from a conflict between simcity_1.dat and the simulator dat, as it is the case with the CAM (about workforce doubling)?"

No, the mechanisms in question are completely different.

EDIT:  I would be especially interested in knowing if you have enough jobs at the proper wealth levels for your Sims.  This wouldn't necessarily show up in the demand graph.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 09, 2009, 05:07:09 PM
sadly, this was a test city and I have already wiped it out....

but I can give some more clues:

- as said, it was a test city. Large tile. Grid pattern, com zones evenly reparted along the main avenues. A large stripe of agri on the north border. Industrial zone in the SW corner.
About 56k residents 1000R$$ all the rest R$ (CAM with optional 5%). 30k ind jobs, 15k commercials. mayor rating above 60 (hospital and police coverage, no schools at all, FD onlyin the industrial zone). Water only in the Ind zone.

-Concerning traffic, some soft congestion (orange) at some intersections but nothing that could freeze totally an entire city.

-All R demand are positive, R$ quite at the top, R$$ slightly less. Comm and Ind demand low but positive.

-abandonment touch about 5 to 10% of the R$ houses (R$$ were too scarce to determine if they are also affected), evenly reparted all around the city.

Hope this little bit of data could help... I promise to shoot my next city from all the points of view^^

PS: to answer your edit, as you can see above, there where plenty of jobs quite double than those needed...
Title: Re: Traffic Simulator Z Development
Post by: z on November 09, 2009, 08:05:22 PM
Water only in the Ind zone.

This could certainly be part of the problem, though in an indirect way.

Did you by any chance install the Park & Ride versions of the simulators?  That's the most common reason for getting this type of problem.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 09, 2009, 11:31:54 PM
I had realized that I hadn't fully answered this part of the question, and I was planning to address it more.  I think that what it comes down to is what you call playing style.  There are two aspects of your playing style that you have publicly described that would explain why you don't see this effect.  First, you tend to play smaller cities than the one I used in my tests, and based on the way A* works, this would make it exponentially less likely that you would see such an effect.  As I mentioned, I went through your whole testing thread, and the only place I saw evidence of this effect was in Nate's city.  But that was by far the largest city in your tests, with all other cities being under a million, as far as I could tell.  So there's a huge connection between the likelihood of this happening and the size of the city, which your tests appear to confirm.  Nate's city when we started was about the same size as my test city.

The second factor is that in your cities, you tend to mix different zone types closely together.  This not only makes paths between Sims and their jobs shorter, but it means that there tend to be a lot of short, valid paths between Sims and their jobs.  This makes the job of the pathfinder much easier.  Combine that with the fact that in smaller cities, there are less paths that need to be searched, and the result is that the pathfinder does not need such a precise setting to find correct paths reliably.

I saw this effect with the Maxis simulator when I first played the game.  On medium-sized tiles, it worked reasonably well for me.  But on large tiles, things really fell apart.  (Please note:  I am not trying to compare the Maxis simulator to Simulator A; I am just comparing this one effect.  Simulator A is obviously vastly superior to the Maxis simulator in just about every conceivable way.)

Is this the quote you are referring to?  Essentially, you have explained to me what I have been trying to make you realize since you made your claim.  It seems to me that play style has a very large effect on what is the proper PH for a person which would really make "Perfect" Pathfinding less relevant than you are making it out to be.  Actually, one of the things I have been noticing is things overall are not as important as we originally assessed. (which would change our job descriptions a bit to be more helpful to others in providing them with information and guidance rather than "build it" for them.)  It seems to me that the play style which is most effected by not having "perfect" PH is where you are building griddy cities in overly populated areas.

http://en.wikipedia.org/wiki/Manhattan

According to this info on Wikipedia of Manhattan Island, one of the densest areas in the world, there is a population density of roughly 28,000 people per square KM.  Which means on the 16 square KM large city tile the densest spot in the world would only have roughly 450,000 Sims.  In real life, Manhattan is a griddy like city with the worst traffic in the world and if you take a look at the zoning, you will see condos next to office towers mixed together throughout the island.  Manhattan would not work without the proximity of home and work, which would only make sense for our game to force you to "shorten" your distance between home and work when you reach these ungodly population levels.  The very thing you have been trying to avoid is the realistic "crunch" of population on commute distance and allow your users to build griddy and make big sections of Residential and Commercial away from each other.  It doesnt work in real life why should it here?

But, then that is my opinion.  You are entitled to yours on what realism is.

This would be why I have been saying Simulator Z is great as a Sandbox Simulator for MDs and why Simulator A is better for those who would like a little more challenge and game play.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 10, 2009, 01:15:47 AM
I've been doing some tests in my Downtown city tile and the results of the tests were not what I was expecting.

Here is a picture of the entire city tile:
(http://img691.imageshack.us/img691/17/sector22.jpg)

The Sim population is ~310,000, while in RL, the equivalent population is < 100,000.

There is a single east-west freeway (Maxis highway) running through the center of the city tile.  Generally, north of the freeway is housing, commecial is to the south of the freeway and industrial jobs are on the southern edge of the map.  This pattern is common among city tiles on the southern shore of my region.  There are suburbs several tiles away and commuters need to skip across city tiles to get to jobs.

Back when I had abandonment problems with this particular city tile, the problem area is the at the center right of the map north of the freeway, where all the high-rises residential are.  There are only a couple of roadways in and out of the area.  I was using Simulator A at the time.  I had thought it was really a traffic problem (commute time).  To solve the abandonment problems, I used Simulator Z and beefed up the number of jobs in the region (particularly, tens of thousands of industrial jobs elsewhere in the region).  The mass abandonment went away, and I gave credit to Simulator Z.  Now that I think about it, it's more likely the increase in jobs did the trick.

I stuck with Simulator Z.  The next issue was getting Sims to work where I prefer them to, without affecting both the visual and functional aspects of the transportation system I built.  Back with Simulator A, Sims were working in the Downtown city tile, but a good chunk of commuters were leaving the city, not working in the same tile they had homes in.  Especially in that high-rise area north of the freeway.  These commuters were going to work in the city tile to the east.  The pattern stayed true with Simulator Z.

There is a huge amount of westbound commuters from the eastern suburbs.  I was able to achieve this after getting the abandonment issue "solved" and using Simulator z.  However, there are a lot of jobs in the Waikiki city tile (east of the Downtown city tile).  These commuters were just skipping that tile, skipping the Downtown tile, skipping the city tile west of Downtown, and I didn't want them to go any further, because there is the potential of an eternal commuter loop by the airport.  In the Downtown city tile, there were thousands of empty jobs, not just in the industrial areas (like I always had), but in the Downtown commercial high-rises as well.  Sims weren't going to those jobs.  I had the thought that Sims were just going to the closest job, but those commercial jobs were closer (to the perspective of the westbound commuter from the east suburbs) compared to the Maxis highway neighbor connection for the city tile to the west.

The simulator used in the following is Simulator Z Classic.  The congestion view was full of red like I'd never seen it before.  Since the network capacities are so low, and buses add to traffic, pedestrian usage was ~ 3/4 the amount of car usage in the city tile, and bus usage was ~ 1/5% the car usage.  Some people do walk 1/2 a mile to work in real life, but not in the range of tens of thousands.

The first test had to do with getting (some) Sims to where I wanted them to work.   A while ago, z suggested to me (quite often) to put rapid transit in my region, as it could "solve" some weird commuting issues (40,000 Sims walking to an avenue connection).  Even with Ultra, thousands of Sims were walking to their jobs, for both intra- and inter-city commutes.  Once Honolulu officially starts building its elevated rapid transit line, Capitalis will have one too.  I had the idea of a secret subway system.  It wouldn't intrude on the non-underground view.  I wanted to see if Sims really went to the "closest, available and appropriate job".

I built several, parallel, express subway north-south corridors.  One station was in the residential areas to the north of the freeway, and the other station was along the southern shore, by the commercial high-rises and industrial areas.  To my surprise, Sims were finally commuting to the southern shore.  Not by the dozens, but by the hundreds.  For these residential areas, the neighbor connections were the closest jobs, but these neighbor connections were extremely overcongested (hitting the 65535 limit).  I connected these parallel subway lines, and the usage jumped to 8000+ on some parts of the lines.  There were some bus commuters from neighboring cities that were transferring, but the overwhelming majority of subway users were residents of the Downtown city tile.  I didn't save the city tile after the test.

Today, I had the urge to try Simulator A again.  So, I replaced the traffic simulator and congestion view plugins.  I put in Simulator A Hard.  To my surprise, things were working out fine, and better than expected.  The westbound city-tile-skipping commuters were actually taking exits off the freeway.  Sims were working at Downtown and (some) industrial areas.  There wasn't abandoment.  I do have to give Simulator Z credit, as it moves traffic away from streets and roads, and on to avenues and highways, and also spreads traffic to alternate routes.  With Simulator A, Sims prefered certain routes, and there were those dreaded shortest-distance paths, but that was because nearby roads were many times over their capacity.  And speaking of cars, car usage was higher compared to Simulator Z Classic, pedestrians were way down, closer to bus usage.  There wasn't the overwhelming bus usage I was expecting, even though buses did not count to traffic.

Now, I'm interested in trying Simulator A in other neighboring city tiles and seeing if the patterns hold.  z, jplumbey, ldog, etc. you all can figure out what this all means.
Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 01:31:15 AM
Is this the quote you are referring to?

Yes, that is the quote I was referring to.

Now there's nothing in Simulator Z that prevents you from playing cities in your style and in a challenging way.  Various efficiencies I've made in Simulator Z have gradually made it require less and less network capacity to function in a challenging way.  This is why I started out with only the Ultra capacity level in my pre-release versions, introduced Low, Medium, and High for the release version, and have recently release Simulator Z Classic, which has half the capacities of the lowest capacity version of Simulator A.  Are you claiming that Simulator A is more challenging than Simulator Z Classic?  If so, on what basis?  The last time I asked you, you had never used Simulator Z.  Have you now?  If so, to what extent?

So although the current versions of Simulator Z will allow a challenging game to be played in all ranges of cities (and I am in the process of preparing documentation from users to back that up), Simulator A restricts users to your playing style, and fails in big cities with big populations.  (I'll address the "realistic" aspect later, with some statistics.)  So Simulator A allows you to play a subset of the cities you can play with Simulator Z.  Specifically, it restricts you to smaller cities with simpler paths - that's what it means to be playable with a higher PH.  So from that point of view, I could call Simulator A a "sandbox simulator," since it restricts you to a much simpler game, and Simulator Z a "more realistic" simulator (which is how many users have characterized it).  But this seems rather pointless to me.  So please, let's just get rid of terms like "sandbox simulator," and stick to verifiable facts.  Along those lines, unless you can prove that the vast majority of usage of Simulator Z is for MDs, which is contrary to what I've seen, please drop that assertion as well.  Repeating assertions not backed by verifiable facts isn't going to get us anywhere.

Quote
According to this info on Wikipedia of Manhattan Island...

We had this exact discussion a year ago, didn't we?  After months of discussion and research, two things emerged:


The second point is supported by measurements made by David while building 3RR.  In a post in this thread made last December 1st, I said,

Quote
However, at one point dedgren concludes (using Chicago as a model, no less!) that population density in SC4 is 10 to 20 times too high; in another example, he concludes it's 10 times too high.  This corresponds with my experience exactly.  Having built a half dozen tiles of Chicago exactly to scale, right down to the streets, with correct zoning, I estimate that if I ever finish it, the total population will be about 30 million - about 10 times too high.  So taking this into account, the aforementioned model of Manhattan-style transport would start applying to SC4 cities somewhere in the 4.3 million to 8.6 million range.

You say here:

Quote
The very thing you have been trying to avoid is the realistic "crunch" of population on commute distance and allow your users to build griddy and make big sections of Residential and Commercial away from each other.

And in an earlier post:

What is happening in the downtown cores around the world which used to be reserved for commercial towers?
At least in Toronto anyways and I am sure in other parts of the world, there are more and more condos (residential units) being built right in the middle of the downtown core.  The initiative is there for the population to live closer to work instead of commute from the "bedroom" communities so that we can reduce traffic, promote walking or MT usage.

The implication I read here is that commute times either have gone down in Toronto or are expected to go down, and that the same is true ("I am sure") in other parts of the world.  No supporting figures are given.

Let's look at the actual figures.

In the issue of Time Magazine dated November 9th, at the bottom of page 11, there is the statement:  "15 minutes [is] the mean amount of time it takes people in Grand Forks, N.D. to get to work - the shortest commute of any U.S. metro area."  That's a one-way commute, so the mean round-trip commute is 30 minutes.  But in SC4, we talk about maximum commutes.  Now the maximum commute for an area is typically much more than twice the mean commute, but we'll be very conservative, and we'll use a figure of twice the mean commute.  This means that the shortest maximum commute of any U.S. metropolitan area is 60 minutes.  And of course, the average maximum commute in the U.S. is much more than that.  Compare this with the 17 minute maximum commute time of Simulator A.

Let's go specifically to Toronto.  You're Canadian; you seem to know Toronto.  But how do the actual figures stack up?  Here are the average round trip commute times for major Canadian cities, courtesy of the Government of Canada (http://www.statcan.gc.ca/pub/89-622-x/2006001/t/4054735-eng.htm):

(http://img23.imageshack.us/img23/8263/cancom.jpg)

So the average round-trip commute time for Toronto commuters is 80 minutes, meaning that the maximum round-trip commute is somewhere over 160 minutes - about a factor of 10 higher than Simulator A's maximum.  Are those condos bringing that number down?  Or are they going to soon?  Here are excerpts from an article from the Toronto Star (http://www.thestar.com/News/article/285168) which use the same figures:

Quote
He's among the growing ranks of extreme commuters in the Toronto area whose daily round trip to work routinely stretches to two hours or more. GTA residents have the longest commutes in the country – up from 68 minutes on average in 1992 to 79 minutes in 2005, according to Statistics Canada.

Experts predict the daily drive will likely get worse before it gets better as the GTA's population grows.

...

He's among the growing ranks of extreme commuters in the Toronto area whose daily round trip to work routinely stretches to two hours or more. GTA residents have the longest commutes in the country – up from 68 minutes on average in 1992 to 79 minutes in 2005, according to Statistics Canada.

Experts predict the daily drive will likely get worse before it gets better as the GTA's population grows.

Every weekday at 5 a.m., just about the time Barrett is arriving at his desk, Jennifer Case is pulling out of her Collingwood driveway with a huge travel mug for the 90-minute trip to Aurora, where she teaches three days a week.

But if she leaves any later than 5 a.m., Case runs into traffic. "Highway 400 is very well travelled by 6:15 a.m. By the time you get to Barrie it is very busy," she says.

Like most long-distance commuters, both Barrett and Case drive alone. Statistics show the farther the commute, the more likely it will be done in a car. Even transit advocates admit the alternative – expanding transit to more remote residential areas – could be contributing to the sprawl it serves.

"There's always a pressure to provide access (to transit) further out of the city. And it's a bit of a chicken-and-egg situation," says Michael Roschlau, president of the Canadian Urban Transit Association.

"It's making it easier to commute longer distances and encourages people to live further away from where they work. Transit is in a sense part of the problem," he said.

But transit isn't even a realistic option for the growing ranks of commuters who, like Barrett and Case, skirt or travel right through the city. These are the commuters who, along with trucking, have turned rush hour into an all-day affair.

Barrett, who's also a trustee of the Durham public school board, used to start work at 6:30 a.m. "Then I moved it to 6 a.m. and then I moved it to 5 a.m. I will not waste my time on the 401," he said. "If I leave the house at 6 a.m. it will take me an hour and a half. If I leave at 7 a.m., I likely won't see Mississauga for between an hour-and-three-quarters and two hours."


By the numbers

In the 1960s a typical suburban household would make 20 per cent of its trips by transit. By 2007 that had sdropped to 10 per cent.

Kilometres of carpool lanes on provincial roads in the Toronto region this year: 39

Kilometres of carpool lanes projected for 2031: 400

Number of car occupants on average in Toronto in the 1970s: 1.25

Number of car occupants in Toronto now: 1.1

Percentage of trips taken on transit in Toronto: 35 per cent

Percentage of trips taken on transit in York Region: 9 per cent

Percentage of Toronto-area residents who say traffic congestion is a severe problem: 41 per cent

Average Toronto-area round trip commute time in 2005: 79 minutes, up from 68 minutes in 1992

Proportion of Toronto-area workers with a round trip commute of an hour or more: 66 per cent

These are official government figures.  And the trend is just getting worse.  That's the real Toronto; the small number of condos built in the city center isn't making a difference, nor is it expected to in the near future.

I've just seen that sumwonyuno has posted.  At first glance, the results seem somewhat anomalous, but it will take time to analyze them.  Question for sumwonyuno:  Are you using Simulator Z v1.2?
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 10, 2009, 01:35:28 AM
I had used Simulator Z Ultra with the latest NAM, then to Simulator Z Ultra v1.2, then I switched to Classic.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 10, 2009, 01:35:42 AM
This could certainly be part of the problem, though in an indirect way.
hum... you'll have to be more factual on this point^^ how could having no water in R$ zones cause abandonment for commute time???

I do not use the P&R.

@jplumbey: your point about manhattan and the role of job proximity is right, but only to a certain extend as manhattan has far more jobs than inhabitants... the quality (I mean design cleverness, not quality in the sense of beautiful and clean^^) of the traffic network is a big factor here... but, indeed, should manhattan shelter only jobs, and every comuters come from the other NY bouroughs, this island would be what ressemble the most to hell  ;)
Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 03:51:41 AM
I had used Simulator Z Ultra with the latest NAM, then to Simulator Z Ultra v1.2, then I switched to Classic.

What you reported in your main post is definitely a bug.  It's either a bug in Simulator Z or the game itself.  But since Simulator A can work properly in your city, there's no reason Simulator Z can't as well.  I can't reproduce the bug here, so I'd really appreciate your help in tracking it down.

I have one good idea about what the bug may be.  Since your city works better with Simulator A (Hard), I've created a special version of Simulator Z (Low) (which has similar capacities) which is modified in a way that may fix this bug.  I've attached this version of the simulator to this post.  I would appreciate it greatly if you would try it out in your main city and see how it works.  You should be able to tell after a few years, at most.


hum... you'll have to be more factual on this point^^ how could having no water in R$ zones cause abandonment for commute time???

As you know, lack of water severely limits the growth stages for all RCI types.  Although it does so symmetrically, this limit means that the game has much less room to play around with to adjust to imbalances in workers and jobs.  In this case, for example, if you ended up with too many workers in your residences, instead of your commercial buildings growing from Stage 3 to Stage 4, they'd just be stuck at Stage 3, and some of your workers wouldn't be able to find jobs.  If this affected enough of them, you'd get abandonment due to commute time.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 10, 2009, 04:55:47 AM
I tried that modified Simulator Z Low with its respective congestion view.  I ran the game for 10 years.  It was pretty much the same as with all the other Simulator Z plugins I've tried.  There was much more of a constrained area for congested streets and the car-ped-bus situation wasn't extreme like with Classic.  However, the commute pattern under Simulator A was not replicated.

Well, I thought such mass inter-city commutes was a feature, not a bug of Simulator Z (because it's intentional and documented).  The commuters will just stick to the freeway because it's fast (even with 65535 cars + buses) and has high capacity compared to the surface streets.  It almost seems as if commuters aren't trying find the closest (available and appropriate) job and then a path to it, but rather the available and appropriate job they can get to the fastest.  I would have to say it has to do with something that's different between Z and A, because the traffic simulator plugin + congestion view are the only things that I've changed do the tests.  The bug is probably related to the issue I have of commuters in the suburbs not going toward the intended job city tiles, but go en masse to a "wrong" city tile (that only has a small clinic and school for jobs).  I'll see if Simulator A makes a difference.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 10, 2009, 04:59:30 AM
but in this case, there are PLENTY of jobs (and buildable empty ind and comm zones alike), and lack of water and education guaranteed from having people needed anything else but D-I, Ag and CS$/CS$$ (and from the appearence of R$$$ wich are a real pain in the a... ^^).
To summarize:

- traffic is almost all green => people should be able to find a job anywhere on the map (
- plenty of desired jobs => people shouldn't be jobless
- according to the others test and witnessing, things are not allways reproductible and they affect both simulators

Stop me if I seem dumb, but this sounds really like an incompatibility bug to me.....  there is somewhere something that interfere with the functions of the simulators, but not for everybody.... JPlumbey talked about "different game styles" having an influence on the effects of the simulators..... actually, game style also have an influence on wich plugins and mods we choose.... if you project to build a very dens urban metropolis, for exemple, you clearly will have very little use of pounds and streams add-ons... if you plan to recrate Phoenix, having hundreds of seaports add-ons would be quite useless, etc... see what I mean?  Maybe, a plugin, used only by certain styles of play is causing a pb?
have anybody noticed this problem with only NAM installed or with only CAM+NAM?


Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 06:07:11 AM
Well, I thought such mass inter-city commutes was a feature, not a bug of Simulator Z (because it's intentional and documented).  The commuters will just stick to the freeway because it's fast (even with 65535 cars + buses) and has high capacity compared to the surface streets.  It almost seems as if commuters aren't trying find the closest (available and appropriate) job and then a path to it, but rather the available and appropriate job they can get to the fastest.  I would have to say it has to do with something that's different between Z and A, because the traffic simulator plugin + congestion view are the only things that I've changed do the tests.  The bug is probably related to the issue I have of commuters in the suburbs not going toward the intended job city tiles, but go en masse to a "wrong" city tile (that only has a small clinic and school for jobs).  I'll see if Simulator A makes a difference.

Well, that test eliminates all the possibilities I can think of for an actual bug in Simulator Z.

I think all your guesses are correct here.  When you say, "It almost seems as if commuters aren't trying find the closest (available and appropriate) job and then a path to it, but rather the available and appropriate job they can get to the fastest," that sounds very likely, because that's what they're supposed to do.  Is it faster for them to get to the next tile than to get to the unused jobs?  That would explain everything.  If I recall correctly, you use streets a lot rather than roads - this would also make this explanation more likely.  And what makes it the most likely explanation of all is that I can't think of anything else.  :D

Fortunately, there's an easy fix.  All you have to do is use Simulator Z (Low) - Local Edition.  Oh yeah, I've got to make it first...  :-\  There!  It's done and attached to the bottom of this post.  Please let me know how it goes.

Maybe, a plugin, used only by certain styles of play is causing a pb?

That's quite possible - if so, it would most likely be a mod of some sort.  Neither the CAM nor the NAM should do this; I wouldn't worry about them.  And from your description, it sounds like you've eliminated my theory about water.

But you say it's not always reproducible, correct?  If you could find out what triggers it, that would be extremely helpful.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 10, 2009, 06:16:27 AM
well, I would try my best for that, but though I agree it "must" be a mod, you can actually put anything you want in a dat file. So nothing can guarantee that an unwanted sim exemplar hadn't been "packed" erroneously in a building dat by an unadvised modder... And I have 3 Go of plugins^^
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 10, 2009, 06:32:18 AM
well, I would try my best for that, but though I agree it "must" be a mod, you can actually put anything you want in a dat file. So nothing can guarantee that an unwanted sim exemplar hadn't been "packed" erroneously in a building dat by an unadvised modder... And I have 3 Go of plugins^^

I've never seen a traffic sim included in a building or lot dat file. Not even on a cheat lot. The only place I can even think you may even possibly run into this is at the Maxis Exchange... but even that's highly unlikely.
I think you should have a careful look through of your plugins, to make sure there isn't an older traffic sim floating about, screwing things up.

Copy this to a txt file and run it through Cleanitol, to speed up the search.
Code: [Select]
*traffic*.*
Z, I hope you're keeping track of all the files you're posting here, so you can add them to a Cleanitol for removal upon the next release?
Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 06:46:19 AM
Z, I hope you're keeping track of all the files you're posting here, so you can add them to a Cleanitol for removal upon the next release?

At this point, since they're all designed for single-use, they have the same names as the standard Z simulators, so they'll automatically be taken care of.
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 10, 2009, 07:09:44 AM
I'd also advise against that. You should rename the files differently, so that if there is an issue with a specific version, you can adjust accordingly. If someone comes to you with a problem about your sim, you don't know if they got it from the LEX, or just 3 pages back. More importantly, if there's a problem with the new sim, and the user needs to go back to the last version... well... simply renaming the file a bit can prevent a lot of confusion.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 10, 2009, 10:18:44 AM
Here you go...  On a rampage again.  Yes, yes I know you think your work is the only work that is good.  Guess what, it is not perfect for all situations.  Capacity of Simulator Z Classic is not what I am talking about for "challenging".  And yes, your Simulator to me constitutes a "Sandbox Simulator" because you can do what ever you want and not suffer from any consequences essentially....  This is what you have been trying to prove right?  No consequences = realistic?  That is where we disagree.

Again, I made my Simulator for ME, not you.  It works fine, and does what it is intended to do.  You should stop comparing them and look at them as if they are attaempting two different things.  Yours fixing all problems that could occur before they occur by way of modding the Simualtor (sandbox), and mine just make a Simulator that suits my style of play and keep the elements of the game intact to some extent.  Im sorry if you think the elements of the game I am talking about are "bad" but then that is your opinion and it is good you are making a Simulator for that group of people.

We had this exact discussion a year ago, didn't we?  After months of discussion and research, two things emerged:

  • The game contains a fairly reliable scale of speeds and distances, based on the fact that a single game square is 16m long.  (At very small scales, the game sacrifices proportion for the sake of visibility, but this does not significantly affect game play.)
  • Population in SC4 cities is not comparable to population in RL cities.

The second point is supported by measurements made by David while building 3RR.  In a post in this thread made last December 1st, I said,

You say here:

And in an earlier post:

The implication I read here is that commute times either have gone down in Toronto or are expected to go down, and that the same is true ("I am sure") in other parts of the world.  No supporting figures are given.

Let's look at the actual figures.

In the issue of Time Magazine dated November 9th, at the bottom of page 11, there is the statement:  "15 minutes [is] the mean amount of time it takes people in Grand Forks, N.D. to get to work - the shortest commute of any U.S. metro area."  That's a one-way commute, so the mean round-trip commute is 30 minutes.  But in SC4, we talk about maximum commutes.  Now the maximum commute for an area is typically much more than twice the mean commute, but we'll be very conservative, and we'll use a figure of twice the mean commute.  This means that the shortest maximum commute of any U.S. metropolitan area is 60 minutes.  And of course, the average maximum commute in the U.S. is much more than that.  Compare this with the 17 minute maximum commute time of Simulator A.

Let's go specifically to Toronto.  You're Canadian; you seem to know Toronto.  But how do the actual figures stack up?  Here are the average round trip commute times for major Canadian cities, courtesy of the Government of Canada (http://www.statcan.gc.ca/pub/89-622-x/2006001/t/4054735-eng.htm):


So the average round-trip commute time for Toronto commuters is 80 minutes, meaning that the maximum round-trip commute is somewhere over 160 minutes - about a factor of 10 higher than Simulator A's maximum.  Are those condos bringing that number down?  Or are they going to soon?  Here are excerpts from an article from the Toronto Star (http://www.thestar.com/News/article/285168) which use the same figures:

These are official government figures.  And the trend is just getting worse.  That's the real Toronto; the small number of condos built in the city center isn't making a difference, nor is it expected to in the near future.

I've just seen that sumwonyuno has posted.  At first glance, the results seem somewhat anomalous, but it will take time to analyze them.  Question for sumwonyuno:  Are you using Simulator Z v1.2?

The problem with your theory is the game does not require an 80 minute commute under any circumstance.  In Simulator A, the longest trip would possibly be the diagonal which is roughly 17 minutes one way by Road (34 minute round trip).  There is no need for any higher than that, period.  You've tested... oh yes, you've tested and you say 600 is the "best"...  You are probably right, if you want to build all your res in one corner and funnell your Sims in a grid to the other corner where the jobs are.  But, it is not the best for me and obviously others who have built Simulators similar to A and B.  We are back to that play style and what is good for each individual again.  Simulator A does not use "real" commute times becuase the game DOESN'T require it.  If you are trying to tell me that Simulator A is unrealistic because it has a commute time of 17 minutes, which I do not believe is minutes by the way simply just a unit of time because there is no time.  If you are trying to tell me that is unrealistic, maybe you should look at your 10 hour commute time as well?  Crap, in trying to show your bias hypocritical side I accidentally attacked one of the values in your Simulator.  Im sorry I was only trying to defend my own work and you put me in that position.

Now, you are disputing what I have said about the zoning in the City of Toronto?

I have said that the City of Toronto currently has about 30 condos under construction downtown, this will allow maybe another 10-20,000 people to live in the downtown core.

I KNOW it is happening because I see it with my own two eyes.  Condos amoungst office towers.  What is the reason for it?  Lower the commute time of *those* people, since it is such a small portion of the population roughly 7 million people in the GTA, it is not going to have a big effect on overall average commute time.  And of course, you must also take into account these people have not moved in yet so your data will not include the new condos I have been talking about.

You are comparing 1992 to 2006 data....  Yes the GTA has a rise in commute time... Do you know why?  Because our population has exploded, meaning the suburbs are sprawling.rediculously!  In the past 5 years is when the idea to start building more condos closer to work has started to take effect.  That is because we are running out of space due to the Green Belt Act, and other forces.  That Act alone force commute time to skyrocket by forcing people to commute to downtown from Barrie.  The City is about to build up instead of out and it is changing, in the way that I have said before.  Re-zoning and putting work closer to home is the way our City is starting to go.

Starting.... As in will have an impact but doesnt yet.  I am pretty sure my claims on this have said the word "starting".

I think I understand what is happening in my City better than you, when you read one article and I lived here my entire life.

Maybe you should go find the stats on the population Density of Toronto...  Then we can compare the bad congestion and bad commutes (how a City works in real life) that Toronto has at this level to how it is handled by Simulator Z with it's green congestion and perky Sims (how a City works in Utopia (fantasy land)).
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 10, 2009, 12:37:09 PM
I've never seen a traffic sim included in a building or lot dat file. Not even on a cheat lot.

I did not mean a deliberately incorporated, but you know how things work when you're a beginner, you take the work from someone else, open it and try to understand the inner things, then you eventually modify it to create your own first.... and some parts of it get stuck in your first try without you notice it.....^^

My plugins are well organized and search for a "rogue" traffic sim was the first thing I did, but I still follow your advice about passing a cleanitol batch... unfortunately, it get nothing.

While at work (SC4D is blocked so I can't post from office), I did analyse the situation a bit: if there is abandonment, it means the game THINKS there is. Wich means the game determined one of two things:

- people don't find jobs (wich couldn't be in this case)
- jobs people have found are more than 300 (600/2) travel ticks away (I definitely agree with JPlumbey about these not being minutes since there is a "convertion unit" in the simulator)

To my opinion, in this instance, this is only possible if one of the following occurs:

- another plugins changes the max time commute after the NAM
- commute simulation is stuck in some sort of eternal loop

I also remembered having read something about road top mass transit lot and how they work, but not exactly where... and I do use RTMTV. Could the kind of "reseting" affecting commuter's routes each time they pass through these lots have an impact on the way the simulators are working (or at least, lead to unexpected effects...)?
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 10, 2009, 01:53:40 PM
Well, that test eliminates all the possibilities I can think of for an actual bug in Simulator Z.

I think all your guesses are correct here.  When you say, "It almost seems as if commuters aren't trying find the closest (available and appropriate) job and then a path to it, but rather the available and appropriate job they can get to the fastest," that sounds very likely, because that's what they're supposed to do.  Is it faster for them to get to the next tile than to get to the unused jobs?  That would explain everything.  If I recall correctly, you use streets a lot rather than roads - this would also make this explanation more likely.  And what makes it the most likely explanation of all is that I can't think of anything else.  :D

Fortunately, there's an easy fix.  All you have to do is use Simulator Z (Low) - Local Edition.  Oh yeah, I've got to make it first...  :-\  There!  It's done and attached to the bottom of this post.  Please let me know how it goes.

That's quite possible - if so, it would most likely be a mod of some sort.  Neither the CAM nor the NAM should do this; I wouldn't worry about them.  And from your description, it sounds like you've eliminated my theory about water.

But you say it's not always reproducible, correct?  If you could find out what triggers it, that would be extremely helpful.

Holy moly, how many "versions" of Simulator Z do you need to make Simulator Z work in "all situations"?  It seems to me you are making more and more "specialized" versions, but yet you claim Simulator Z is perfect for every situation.

Random User Who Likes Simulator A - "Oh... I like Simulator A because of ....."
Steve (Z) - "O really, that simply is not acceptable Simulator Z can handle this...  All I have to do is make a simple quick change voila and here it is."
Jason (JPlumbley) - *Rolls Eyes yet again*
Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 02:02:40 PM
I will get to Jason's comments later.

I definitely agree with JPlumbey about these not being minutes since there is a "convertion unit" in the simulator.

The conversion unit in the simulator is not used by the game in any way whatsoever.  This has been verified by many people.  Try setting it to any value you like, and you'll see that nothing in your game changes.

Quote
I also remembered having read something about road top mass transit lot and how they work, but not exactly where... and I do use RTMTV. Could the kind of "reseting" affecting commuter's routes each time they pass through these lots have an impact on the way the simulators are working (or at least, lead to unexpected effects...)?

The "resetting" was a theory of Jason's, promoted as fact, that was disproven by a number experiments a year ago.  RTMT has no more effect on the traffic simulators than any other transit stations.
Title: Re: Traffic Simulator Z Development
Post by: xxdita on November 10, 2009, 02:12:46 PM
RTMT has no more effect on the traffic simulators than any other transit stations.


Not completely true. The capacity set by the RTMT lots greatly effect the traffic flow at that point in the road. If the capacity of the RTMT isn't set to match up with the traffic simulator in use, then you've now limited the flow of traffic between these RTMT stops, forcing anything over that capacity to find an alternate route. Unless of course you're providing a set of RTMT for every traffic sim?
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 10, 2009, 02:13:20 PM
I tried the latest modified Simulator Z Low and there's still tens of thousands of Sims commuting through and past the Downtown city tile.  Jobs aren't being taken because the commuters aren't exiting off the freeway.

There are 4 westbound offramps in that city tile, 2 of which only make sense for getting to jobs.  The first encountered offramp leads to an overcongested north-south roadway that also serves the high-rise area north of the freeway.  So, I thought that freeway commuters weren't getting off because of that roadway.  However, the next exit (which leads into the main avenue into Downtown) is barely used.  Only a hundred or so commuters get off at that exit.  When I tested with Simulator A, nearly all of the remaining westbound commuters got off at this offramp.  So what about the roads between that offramp and jobs?  Those roadways aren't even yellow this time.  With other versions of Simulator Z, there is much more usage on the roadways in this part of town.  I'm not sure what you're changing with the versions you're asking me.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 10, 2009, 02:20:53 PM
The "resetting" was a theory of Jason's, promoted as fact, that was disproven by a number experiments a year ago.  RTMT has no more effect on the traffic simulators than any other transit stations.

Stop mis-quoting...  I did not say RTMT was worse than other transit stations.  I said ALL transit stations, and RTMT was only bad because it forced all Sims on the given route into the station, whereas if it was not on the route itself it could be bypassed.

The theory was based off of the thing we see all the time in game, Sims walking to a bus station in Maximum Commute, then doing a second commute from Bus station A to Bus station B, then a third commute of Maximum Commute walking to work from Bus station B.  It is still a relevant theory for Mass Transit Commutes, all that was proved was "through-commutes" which dont use that transit switch from one type to another type are not effected by this "reset".

Not completely true. The capacity set by the RTMT lots greatly effect the traffic flow at that point in the road. If the capacity of the RTMT isn't set to match up with the traffic simulator in use, then you've now limited the flow of traffic between these RTMT stops, forcing anything over that capacity to find an alternate route. Unless of course you're providing a set of RTMT for every traffic sim?

Also, dont forget that the different traffic types through these lots have different speeds but only one speed may be satisfied by the Transit Switch Cost.  Meaning if it is set for the speed of cars, busses and walkers (at default speeds) are set to gain an advantage for that one tile.

I tried the latest modified Simulator Z Low and there's still tens of thousands of Sims commuting through and past the Downtown city tile.  Jobs aren't being taken because the commuters aren't exiting off the freeway.

There are 4 westbound offramps in that city tile, 2 of which only make sense for getting to jobs.  The first encountered offramp leads to an overcongested north-south roadway that also serves the high-rise area north of the freeway.  So, I thought that freeway commuters weren't getting off because of that roadway.  However, the next exit (which leads into the main avenue into Downtown) is barely used.  Only a hundred or so commuters get off at that exit.  When I tested with Simulator A, nearly all of the remaining westbound commuters got off at this offramp.  So what about the roads between that offramp and jobs?  Those roadways aren't even yellow this time.  With other versions of Simulator Z, there is much more usage on the roadways in this part of town.  I'm not sure what you're changing with the versions you're asking me.

He should probably be changing the Commute Time to get the same effect of Simulator A, but remember 600 is the perfect value.  Simulator A was not designed to promote Sims to go from one neighbor connection to another, which is probably why they are finding the jobs in town because they simply are forced into travelling too far to reach the other city border.  Lowering the Commute Time in Simulator Z to something much lower but maybe higher than Simulator A will most likely fix that problem.

Sorry, looking at the modified Simulator Z Low... that is what he did, there must be something else that is wrong with Simulator Z in this circumstance.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 10, 2009, 03:25:03 PM
but in this case, there are PLENTY of jobs (and buildable empty ind and comm zones alike),



keep in mind the CAM has the demand bug , where the game see the residential capacity as doubled..
So in essence you need twice as many jobs for a given population with CAM as in the vanilla game.. I
know what you mean , i have some pretty large cities of my own and if you look around my cities I
have areas of big commercial and sometimes Industrials with plenty of available jobs and no workers,,
but because of the demand bug you need that situation to insure enough jobs..
Im using the Cam now for a couple of years with these cities . also
Im using sim Z (low) without any issues. I have 3 cities in my region over a million..

thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 10, 2009, 03:58:09 PM
keep in mind the CAM has the demand bug , where the game see the residential capacity as doubled..

actually my CAM dat is merged with simcity_1.dat, so this bug is not active here (in fact, I decided to try the merge trick a few weeks ago in the hope it could fix my abandonment problem)

anyway, I use the census vault, wich give the real workforce and the real available jobs, to collect pop and jobs data.
Title: Re: Traffic Simulator Z Development
Post by: z on November 10, 2009, 11:57:10 PM
Not completely true. The capacity set by the RTMT lots greatly effect the traffic flow at that point in the road. If the capacity of the RTMT isn't set to match up with the traffic simulator in use, then you've now limited the flow of traffic between these RTMT stops, forcing anything over that capacity to find an alternate route. Unless of course you're providing a set of RTMT for every traffic sim?

This is not the way transit stations work.

First of all, as of the RTMT v3.51 patch issued in January, there are two capacity levels for each station:  Low and High.  To quote from the Readme file:

Quote
The Low capacity version is designed for rural areas and/or small- or medium-sized towns; it is basically designed for regions where there will never be a need for a traffic simulator with a capacity higher than the Hard version of Simulators A or B, or the Low version of Simulator Z.  In numerical terms, this translates into a road capacity of about 2500.  The High capacity version of RTMT stations is designed for all regions above that limit.

Second, transit stations don't get congested the way the game displays them, and the "Service quality" icons are completely inaccurate.  The service quality of a station at 200% capacity is just as good as the service quality at 1% - both have perfect service quality.  There is simply an undocumented limit that varies by station as to how many passengers per day the station will accept.  The minimum appears to be 400% of station capacity.  Once that minimum is reached, the station accepts no more passengers for the day.  This has been verified by many people in many different experiments.  This is also why, at least in RTMT, the inaccurate term "Service quality" has been replaced by the somewhat more accurate term "Reserve capacity."

The RTMT station capacities have been set so that these actual limits should never be reached.  Neither I nor the RTMT testers have ever seen this limit exceeded.



As for Jason's posts, though there is much to respond to there, my responses do not seem to have been helpful up until now, and I have no reason to expect that this will change.  It has come to the point where it does not seem productive for me to participate here any more.  So I will be taking my leave from this site for now.  I should know soon whether this leave is temporary or permanent.  In either case, you should hear from me at least one more time.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 11, 2009, 04:49:28 AM
Not completely true. The capacity set by the RTMT lots greatly effect the traffic flow at that point in the road. If the capacity of the RTMT isn't set to match up with the traffic simulator in use, then you've now limited the flow of traffic between these RTMT stops, forcing anything over that capacity to find an alternate route. Unless of course you're providing a set of RTMT for every traffic sim?

Do this means that to be really perfect, you have to modify all your RTMT pieces to exactly match your own simulator capacity values?
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 11, 2009, 05:10:13 AM



As for Jason's posts, though there is much to respond to there, my responses do not seem to have been helpful up until now, and I have no reason to expect that this will change.  It has come to the point where it does not seem productive for me to participate here any more.  So I will be taking my leave from this site for now.  I should know soon whether this leave is temporary or permanent.  In either case, you should hear from me at least one more time.

     I look forward to hearing from you soon Steve.. I know I echo the sentiments of others that should you
decide you want to leave permanently it will be a great loss to myself personally , to others involved in traffic
and transit, to the website as a whole, and to the game itself as it has evolved since you helped change it ...
in improved ways through your work both with traffic research and great work, improvements, and efforts you
have brought to road top mass transit .. I hope you will reconsider your postition here with us , as I am quite
sure your work is not yet finished here with us.. However ,  I respect your desires and wishes on a personal level
and should you decide to leave us in a permanent nature, id like to thank you for the help you have given others
through your excellent postings through the years now  and for all of us to better understand how traffic works in our game because you took the time to explain it .. I think you will be sorely missed by others here and your
work ethic and commitment to the site to make this a high quality web site (along with others here), is such
that it could never be replaced..

Your devoted friend, Brian 
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 11, 2009, 06:52:19 AM
It is really amazing how ego considerations could ruin even the best efforts!
Z and Jplumbey, you are both great moders, and I'm sure all the community would agree to say your respective work and discoveries have been utmost for us all... Why the hell are you waring at each other like that?!? Do any of you have financial interest concerning the use of his own created simulator??? Is there a price for being the creator of the one and only simulator used in the NAM???
The reality is that there are many game style and thus the need for several traffic simulator, each adapted for a different styles... There is room for the both of you in this community and you  not even have to apreciate each other... Just keep improving your work, each with his own fans and detractors! I even hope we'll soon have more different simulators...
But please, stop this ridiculous fight! None of your sim is better than the other, they only have different goals!
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 11, 2009, 10:11:41 AM
Do any of you have financial interest concerning the use of his own created simulator??? Is there a price for being the creator of the one and only simulator used in the NAM???
The reality is that there are many game style and thus the need for several traffic simulator, each adapted for a different styles... There is room for the both of you in this community and you  not even have to apreciate each other... Just keep improving your work, each with his own fans and detractors! I even hope we'll soon have more different simulators...
But please, stop this ridiculous fight! None of your sim is better than the other, they only have different goals!

No there is no financial gain.  I have not once said there should only be one Simulator in the NAM, in fact I am fighting to keep that choice there and I agree with you that I hope to see more people like Lenny trying to understand the Simulator and make their own for the Community.  I learned that lesson last year, and I definitely tried not to fight with Steve again this year but I got dragged in by his comments about my work and my posts which generally were not directed to him at first.  I have noticed a lot of the same attitude and response to critism from Steve that I had last year towards him, and I took almost a year away to come back and realize that it doesnt matter who's Simulator is better.  My intent here was not to attack Simulator Z or get into a direct confrontation with Steve and up until yesterday I did fairly well at that....  My intent was to help Steve realize that there is room for all the Simulators something he has started to come around in by finally making a suggestion to keep both Simulator A, Z and the Maxis Default Simulator in the NAM while removing all the other choices.  And I also wanted Steve to stop touting his Simulator as the best in all situations, while attacking Simulator A as sub-par.

All I have been looking for is for him to see that there is no "perfect" Simulator, and for him to give the credit to Simulator A it deserves and stop bashing it as he has for the last year with impunity.  I admit he is making strides and has come around saying Simulator A is good, but still has made his attacking remarks about it and I thought we were getting close to a truce on that until yesterday.  On the "perfect" Simulator idea though, I do not believe we have made any headway on that one, unfortunately.

It will be a good thing for Steve to take some time away, as I did last year.  Clear his mind, reflect on some things and come back hopefully with a rejuvenated desire to continue his work....  I just hope he realizes how insignificant this is though.
Title: Re: Traffic Simulator Z Development
Post by: Blue Lightning on November 11, 2009, 02:53:57 PM
The thing is... both of your simulators do a great job in tweaking the internal traffic engine of SC4. Sim A was with me when I was building my largest city ever (2.5 million sims). Sim Z brought me through my most ambitious region-wide transit project. Both situations loaded the simulator quite a bit but they both ended up running them next to perfectly. I had not experienced mass abandonment and redevelopment cycles, huge traffic bottlenecks (only localized ones, in the places you would expect them to be), or any sort of major issue. And this isn't because I adapt my building style to the simulators (I've been playing with the same basic ideas for a long while now, with some new things here and there, but the core is still the same).

Sim A and Z are both great simulators, I must say that. Both Jason and Steve, you two have done a great job in building these. Though the conflicts really don't seem to be doing any good to either.

I've seen projects at other sites (not related to SC4) where projects have gone down the drain because of people in the same team come up with different ways to, for example with a community game I followed a few years ago, build a physics engine for a game. Both ways were perfectly valid and would have worked, with having their own strengths and weaknesses, but neither could have been used and developed further since the two developers were constantly quarreling. The game ended up stalling in development.

Jason, Steve, I'd like to ask you two if this conflict is really helping you, your simulator, or the community. I can imagine that this is not helping the advancement very much, and this is getting in the way of people wishing to learn about traffic simulators, and those who are choosing. Now remember, I'm not placing blame on either one of you.

All I ask is that you two please, drop this and accept each other and his simulator the way they are. Cool off and continue making advancement in the area of traffic simulators. You two may be taking different paths, but they both lead to the same place. Its just a matter of style. Neither is wrong, but both are right.

Now Steve, I personally don't want someone like you, who has contributed so much, to leave. However, if you really feel the need to take a break, I can accept that. Sometimes we all need a break from our tireless efforts.
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 11, 2009, 02:59:34 PM
All I ask is that you two please, drop this and accept each other and his simulator the way they are. Cool off and continue making advancement in the area of traffic simulators. You two may be taking different paths, but they both lead to the same place. Its just a matter of style. Neither is wrong, but both are right.

This is exactly what I have been trying to say....  All I want is for Steve to stop putting down my work while promoting his and accept it.  That is all that has had to happen, but it has not yet happened.  I have already accepted his as good work, all you have to do is read my posts over the last few weeks to see it.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 11, 2009, 03:58:20 PM
z,

I would be at a loss if you did permanently leave this site and all other Simcity fansites.  A break is welcomed if you need one.  You have contributed more to the game than I ever will.  There are numerous things about the game mechanics that I learned from your work.  I've been an advocate of Simulator Z ever since I found it a while (a year?) ago.  I did not mean my latest test findings to refute all of the testings that you've done.

Isn't the difference among the traffic simulator plugins just the collective changes of the exemplar values?  That makes it all seem trivial, as it's not about designing completely different algorithms, but just varied changes to the input of the same algorithm.  Given either Simulator A or Z and a city tile of my region as input, the game will still do its job.  Now, Simulator Z does a good job at showing how inadequate the transportation network of Capitalis is and highlighting the available and appropriate job a Sim can get to the fastest.  For any traffic simulator, what may be the merits and consequences of one city tile, may be the complete opposite of another.

I wouldn't want the NAM to just have one traffic simulator.  If that traffic simulator customization tool comes out, I do hope there's presets.  If the goal is for the benefit of the (diverse gameplay style) community, the outcome of a competition for the one "best" traffic simulator isn't going to be a benefit to everyone in the community because of diverse gamplay styles out there.  It doesn't matter who apologizes to who, explicitly or implicitly.  It just matters if there is a mutual understanding between you and jplumbey that any discussion that devolves to the point of personal politics isn't going to do anyone any good.  Both of you are good (in understanding the game) and both of you show that you both can bring much bounty to the table that is SC4Devotion.com.
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 11, 2009, 05:46:22 PM
Jason and Steve, it's a pity you always have to fight.
It makes it even harder to find and understand the results of all your hard work.


Now, it's taken me till today to completely read and understand Steve's testing November 7th (http://sc4devotion.com/forums/index.php?topic=5382.msg286055#msg286055) (and the follow-ups on that).
Steve, a huge kudos to you for actually taking your time to make these extensive tests.
At least I am convinced that the pathfinding heuristic does play a significant role.
Also the influence of the Max Commute Time on the computing time was quite interesting and well presented.

However, I wish you would stop starting your posts by promising the solution to all problems we've ever had.
If there's something we've learnt by now, it should be that there is no (and never will be a) single ultimately best version of a traffic simulator that suits everyone.


Jason, you need to give Steve credit for his testing as well.
At least he is wasting a lot more time than you doing them.

However, your posts following those tests is where the level of the discussion started to deteriorate.
Instead of commenting on the main results of the tests, you focused on nitpicking on jokes you didn't understand, relations to R$$$ demand and whatever...
You know, you don't have to live up to that Plum Fierce CML of yours...

Btw, I would love to see a Simulator A with a lower PH.
Shouldn't Steve's testing lead to you testing Sim A yourself with a lower PH?


Then over to sumwonyuno's excellent and valuable testing November 10th (http://sc4devotion.com/forums/index.php?topic=5382.300#msg286817).
That perfectly demonstrated the side-effects of having an "unlimited" maximum commute and too high network capacities.
In your case you did not experience eternal commuters around corners, you got them going straight through the whole city tile.

At this point I have to confess that I have for some time had concerns regarding Simulator Z and its influence on eternal commuters,
and I'm glad sumwonyuno so clearly brought this out in the daylight.

Steve, I know you feel a bit cornered here and I hope you could take a deep breath before your next post.
I don't think there is a solution that in the same simulator would both solve the above problem and allow your highly marketed intercity commute.
Title: Re: Traffic Simulator Z Development
Post by: z on November 11, 2009, 06:33:50 PM
A brief technical note here...

However, I wish you would stop starting your posts by promising the solution to all problems we've ever had.
If there's something we've learnt by now, it should be that there is no (and never will be a) single ultimately best version of a traffic simulator that suits everyone.

I tried to frame all of these tests in terms of testing parameters used in the simulator, not the simulators themselves.  When this didn't appear clear in the reactions to my first test, I specifically added it in the disclaimer to the second.

I agree completely that "there is no (and never will be a) single ultimately best version of a traffic simulator that suits everyone."  Even for users of Simulator Z, there would have to be too many versions in order to perfectly suit every situation.  I was starting to explore a whole different approach, based on the use of the NAM Tool or something like it, and elaborated by concepts introduced by Jonathan and Andreas, that would allow the proper simulator to be custom-built for users at installation time and based on their needs.  It would not be Simulator Z or Simulator A; it would be a whole different approach to simulators.  But to do that requires extensive understanding of what the relevant parameters in the simulator do.  Hence my tests.

Quote
Then over to sumwonyuno's excellent and valuable testing November 10th (http://sc4devotion.com/forums/index.php?topic=5382.300#msg286817).
That perfectly demonstrated the side-effects of having an "unlimited" maximum commute and too high network capacities.
In your case you did not experience eternal commuters around corners, you got them going straight through the whole city tile.

At this point I have to confess that I have for some time had concerns regarding Simulator Z and its influence on eternal commuters,
and I'm glad sumwonyuno so clearly brought this out in the daylight.

The high commute time is one of the first possibilities that occurred to me as well.  That's why the second file I sent to sumwonyuno had a commute time slightly lower than that of Simulator A, with capacities very similar to that of the version of Simulator A that worked (Simulator A (Hard) & Simulator Z (Low)).  I was surprised to find that this did not help at all.  But this would seem to rule out high commute time and high capacities as the problem, as these did not exist in that test.

I would have liked to continue the testing to find out what the problem is, but by this point, things had gotten pretty much out of control.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 11, 2009, 08:11:40 PM
RippleJet, z clarified what I was going to say.  There is the issue I descibed in the second test of November 10th (the 9th where I live).  At face value, it seems like a bad thing for Simulator Z, but I wouldn't jump to that conclusion.  Whether I used Ultra, High, Medium, Low or Classic, the behavior is still there.  Network capacities and commute time were ruled out.  I would guess it's some other exemplar property value that's the cause of the issue.

I can't remember where, but I asked z sometime before about neighbor connection jobs.  If Sims were going to the closest (available and appropriate) job, then for a particular area of the city tile, all neighbor Sims that get sent to the same neighboring city tile should be taking the same path to there.  But that wasn't the case.  Sims were crossing the freeway and taking other neighbor connections.  Even for neighbor connections on adjacent tiles, Sims weren't choosing the closest.  z thought it was some randomness in the simulator.

So under Simulator Z (any version), for some reason, Sims weren't going to the south shore to work and westbound commuters from the eastern suburbs were skipping the Downtown city tile.  With Simulator A, this behavior did not exist.  The first test I did on November 9/10 was the secret subway.  I did get Sims to work on the southern shore with Simulator Z.  Even some westbound-freeway bus riders got off the freeway and transferred to the secret subway.

I made a statement on page 16 that z agreed upon:
Quote
It almost seems as if commuters aren't trying find the closest (available and appropriate) job and then a path to it, but rather the available and appropriate job they can get to the fastest.

z then stated "Is it faster for them to get to the next tile than to get to the unused jobs?  That would explain everything."

It's established that Maxis used A* Manhattan pathfinding.  There is the assumption of a start point and a destination point.  A path must exist that includes those two points for a Sim to be employed at an appropriate and available job.  I've come to believe that the assumption that the destination is the closest (available and appropriate) job isn't necessarily correct.  If the closest (available and appropriate) job always holds true, then it wouldn't matter if I used Simulator A or Z.  The commercial jobs to the south of the freeway are always "closer" to the westbound commuters than the Maxis highway neighbor connection on the opposite city tile edge.

If closest job assumption is correct, how would that work?  Would the destination-determiner do closest by Euclidean distance, path distance or random?  Euclidean distance would probably have to do radii around a Sim's building.  But then, the Euclidean distance is ruled out because of those "ignored" jobs in the city tile.  Random would be a good candidate for destination-determiner, but it's quite common to see all commuters of a residential building work at the same employment building.  So what about path distance?  Speed of network wouldn't be a consideration, and we'd essentially be at shortest path pathfinding.  The traffic simulator would have to iterate through the possibilities of 1 to X tile lengths and pick whatever comes first, but that's extremely inefficient route to take.

Back to assertion I made, the available and appropriate job a commuter can get to the fastest answers the destination question and the pathfinding problem.  A* does find the fastest path from a start to a destination point.  Then, from what I gather, the traffic simulator would not have a predetermined destation point; the traffic simulator finds a destination as it's going through A* Manhattan.  Under that idea, for Simulator A, it's faster for the westbound freeway commuters to get off the freeway and take the jobs in the city tile.  For Simulator Z, it's faster for the same commuters to stay on the freeway.  With the secret subway test, it was faster for the Sims living in the high-rise residential area to take the secret subway to the southern shore than to crowd the neighbor connections of the city tile to the east.

Relatively speaking, Capitalis only has a few high-capacity east-west thoroughfares in a general east-west linear city layout.  North-south roadways don't have the capacity to handle both north-south commuters and east-west commuters that turn left/right to get to jobs.  So, traffic simulator is going to have to work with the limited number of alternate routes for a dense and linear urban region.

Anyone, feel free to add or criticize.

[EDIT]

I dug through the pages of this thread and found pictures of my region:

(http://img20.imageshack.us/img20/708/zoning.jpg)

With Simulator Z Ultra beta 2 Road Volume:
(http://img198.imageshack.us/img198/7145/updroad.jpg)

Even though the above picture was from another test, the city-tile-skip issue is still there.

There is the single Maxis highway through the middle of these 3 city tiles.  Almost all of that red is westbound commuters from the suburbs to the east.  The one red north-south roadway is from the high-rise residential commuters from the Downtown (center) city tile that have decided to work in Waikiki.  The commuters aren't getting off the freeway, even though the surface streets leading away from freeway aren't congested with Ultra.

[EDIT 2]

I understand the congestion views do not have the same volume values, so I kept them in the pictures.

Simulator Z Classic - Car Volume
(http://img691.imageshack.us/img691/2131/zcar.jpg)
Simulator A Hard - Car Volume
(http://img689.imageshack.us/img689/1215/acar.jpg)

The thing to notice is the area to the southwest of the crater.  With Simulator Z, the westbound freeway has about 40,000 cars.  Only about 3000 cars get off the freeway, and the remaining 37,000 cars continue on to the city tile to the west.  With Simulator A, the westbound lanes of the freeway have about 30,000 cars and almost all of those cars exit off the freeway.

Here are the bus volume views.  I don't know what conclusions to get from these results.

Simulator Z Classic - Bus Volume
(http://img694.imageshack.us/img694/2453/zbus.jpg)
Simulator A Hard - Bus Volume
(http://img697.imageshack.us/img697/8302/abus.jpg)
Title: Re: Traffic Simulator Z Development
Post by: jplumbley on November 11, 2009, 10:02:04 PM
However, your posts following those tests is where the level of the discussion started to deteriorate.
Instead of commenting on the main results of the tests, you focused on nitpicking on jokes you didn't understand, relations to R$$$ demand and whatever...

Needless, classless jokes especially when the person knows the history is outright wrong.  And yes I will call him on it every time he does, and any other person who does.  I would never crack a joke in a situation like this about the person who I have had problems in the past with.  I believe he knew exactly what he was doing was wrong, if he didnt... well, I cant say what I think then.

Nitpicking, isnt that how you are supposed to analyze a test you have done?  Look for all the things that could have caused the results and determine whether they could or could not have affected your outcome...  I was trying to contribute and it didnt seem to me Steve had thought about those things and was looking for results that would prove him right and jumping to conclusions.

I feel the discussion deteriorated prior to my responses on his tests, but that is just my opinion and if you want me to point out where I can easily do so.

Btw, I would love to see a Simulator A with a lower PH.
Shouldn't Steve's testing lead to you testing Sim A yourself with a lower PH?

Im sorry if I havent made one fast enough for you.  I have not had the issues Steve has reported, how would you like me to test them in the first place if I do not experience them in my cities.  None of my regions, let alone cities reach the population he does in one city tile, where the problem is most likely to occur.  I have no ability to test it if I wanted to, unless I built a multi-million Sim city which I have never reached because that is not the way I play.

Based off of Steve's testing I have been asking questions analyzing his tests with my own questions (focusing on the so-called nitpicking topics) trying to understand what is happening since what Steve shows is not always the whole picture.  Not saying he is hiding anything, but maybe something he notices but neglects to add in his posts because he simply forgot or thought it was obvious or something he simply missed (we all do it).  I have definitely been thinking about making a Simulator A with the .003 PH, but I wanted more answers first.

But, since I am too lazy and cannot reproduce his experiences with my own cities, then I have doubts that must be answered.

You know, you don't have to live up to that Plum Fierce CML of yours...

I didnt give myself that CML...  I had a idea why it was given to me, now I know.

Title: Re: Traffic Simulator Z Development
Post by: ldog on November 15, 2009, 02:31:04 PM
Well, as people might have noticed I dropped out of this conversation right after things started really going downhill.
While I still had things to say, I did not feel they would do anything but add fuel to the fire.
And apparently that fire already had more than enough fuel.

Tage, I think you summed it up pretty well (that video was priceless  ;D ), although you were maybe a little bit harder on Jason than he deserved, but I agree with the points made.
Pharaeon also makes some good points.

All of us involved were getting defensive, which inevitably leads to the counter-attacks that usually turn into full fledged wars.

While I have made my apologies to Steve in pm for my part in the whole thing, I have still felt that some sort of public apology should be made.

Intentions may be good, but it is very hard to see intentions across the forum. We only see words and their effects. While I still respectfully disagree on several points, I think there has been too much emphasis on disagree and not enough on respect. I think maybe that might be true for some others around here as well, but as we are all presumably adults here I will leave everyone else to their own discretion.

This bickering doesn't do any of us any good. It is a waste of time we could all put to better use.
It certainly isn't worth losing someone who brings a lot to the table over.

Anyway, that's enough candy-ass heartfelt touchy feely diplomatic stuff for one day; I'm gonna go back to being a jerk now before someone comes and takes my "man card" away, mmkay  :P
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 15, 2009, 03:01:38 PM
The high commute time is one of the first possibilities that occurred to me as well.  That's why the second file I sent to sumwonyuno had a commute time slightly lower than that of Simulator A, with capacities very similar to that of the version of Simulator A that worked (Simulator A (Hard) & Simulator Z (Low)).  I was surprised to find that this did not help at all.  But this would seem to rule out high commute time and high capacities as the problem, as these did not exist in that test.

I would have liked to continue the testing to find out what the problem is, but by this point, things had gotten pretty much out of control.

Steve, I would very much like to see a continuation regarding this discussion.
Let me also ensure that things now are under control in here.
Title: Re: Traffic Simulator Z Development
Post by: z on November 16, 2009, 03:59:34 AM
Steve, I would very much like to see a continuation regarding this discussion.
Let me also ensure that things now are under control in here.

I will be happy to continue this discussion.  I've been using the break during the last few days to build my new computer, though, and right now, everything's in pieces all over the place.  (This is my laptop that I'm writing from, which doesn't have any of my notes or files.)  It will probably be around the end of the week before I get everything back together enough to do anything useful, but you'll hear from me as soon as I do.

In the mean time, I'd like to offer my apologies to the community for my part in the problems that have arisen.  I think ldog made some very good points in his post, and I wanted to say that I particularly agree with what he said about intentions and respect.  I have no question that everyone involved had good intentions in that we all want to make this a better game for the community.  I also believe strongly in the absolute importance of respect for everyone, but I know I have a style that can become argumentative in a way that is not at all helpful, and I think it's pretty obvious how that trait contributed to the current situation.  In addition, I've noticed how my approach in general can be unskillful at times, and create unnecessary contention.  Again, I apologize.  And more than that, I want to assure the community that in addition to working to create high quality content for the game, I will be working just as much to support harmony in this community, which of course is essential if we are to flourish.  I look forward to continuing to work with the community, and specifically to contribute to the whole range of qualities that make this such a great site.
Title: Re: Traffic Simulator Z Development
Post by: Pharaon-Kheops on November 16, 2009, 05:25:45 AM
Well, that's a very good thing, Z... It would really be a sin to see you and JPlumbey unable to accomodate each other. The community needs the both of you precisely because you are heading toward different directions. As he said, his simulator is created for tile by tile region play, while yours is trying to find a way to play regions as metro areas. Personnaly, I'd rather play in the second category, but I definitely can't deny that sim A did solve many of my traffic problems at the time it did appear...

There is one and only one way to succed in your respective work guys.... this way is called Cooperation!  ;)
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 16, 2009, 06:12:54 PM



Intentions may be good, but it is very hard to see intentions across the forum. We only see words and their effects. While I still respectfully disagree on several points, I think there has been too much emphasis on disagree and not enough on respect. I think maybe that might be true for some others around here as well, but as we are all presumably adults here I will leave everyone else to their own discretion.



I know this is the traffic thread.. and we will get back to that shortly...
but these words are about as well spoken and mean so much as anything ive seen in these forums..
Im very proud of you Lenny for this, if you dont mind me saying that to you :)

Brian
Title: Re: Traffic Simulator Z Development
Post by: z on November 24, 2009, 10:43:15 PM
Steve, I would very much like to see a continuation regarding this discussion.

I had sumwonyuno do a few experiments with his region after he made his last post.  The most surprising thing came out of the first test, which showed that there's a whole side of the traffic simulator that no one knew existed.  These experiments verified some of the things that sumwonyuno said, while disproving others.

First, I'll start with a description of what I now understand of how the traffic simulator works, followed by the evidence I have.  The traffic simulator contains the following two sequential parts:


Until now, virtually all of the discussion and research with the traffic simulator had to do with the second part; this is where A* pathfinding, network capacities and speeds, etc. all come in.  Little was known about the first part.  Some people, like sumwonyuno, guessed that it took place simultaneously with the second part - that Sims could change their destination in the middle of a journey.  But on one hand, this is very difficult to fit in with the way that A* works.  More importantly, there is fairly conclusive evidence that these parts are indeed sequential.

So how does the traffic simulator select an appropriate destination?  There are standard factors such as matching up wealth types and looking at desirability.  Beyond that, it was assumed by many (including myself) that the simulator would look for the closest appropriate destination.  Since Maxis has stated that efficiency in the simulator was paramount, a simple method would need to be used.  The Euclidean (straight-line) distance presents itself as an obvious choice here.  It requires relatively few calculations, and will give a reasonably good answer.  The following test that I did about a year ago also gives strong evidence that that's what's happening:

In my Chicago region, I had a very bad eternal commuter loop.  Sims would enter the Downtown city at one corner, travel just a dozen squares or so, and exit into the next city.  Meanwhile, in the middle of my large Downtown tile, there were all these large office buildings standing vacant.  So I tried to get the Sims to go to them instead.  I cut all the connections between the incoming city and Downtown except for the one heavily used subway line, and then made that turn toward the middle of the tile.  I removed stations along the way, so that the Sims had to stay on the subway.  But when they finally emerged, they'd turn around and find some way to get back to the original crossing point into the third city.  I extended this "express subway" until it was at the edge of the central business district, but it made no difference; the Sims still turned around and headed out of the city.

At the time, I was quite perplexed by this behavior.  Now it makes sense.  When the simulator wanted to find a destination for the Sims entering the city, it just looked at the shortest Euclidean distance, and decided that the next city over made sense.  It didn't know or care that the Sims would have to do a long detour bringing them much closer to the empty skyscrapers than the third city boundary.  That part of the path wouldn't be known until the second part of the simulator ran, and had to create the long, tortuous path.  At that point, the destination was already fixed and could not be changed; the second part of the pathfinder could only determine the best way to get there.  And the big skyscrapers remained empty.

You can also see that the destination finder and the pathfinder may run at different intervals.  The pathfinder runs every four months or so and recomputes all the paths.  The destination finder may run as often, but only needs to run when there are Sims needing new jobs.

None of this presents a major problem.  The eternal commuter loop is well understood, and there are various ways around it; in my particular case, moving the allowed connection to the center of the tile edge made the central downtown area an attractive destination.

So all seemed well and good, and everything seemed reasonably well understood, until sumwonyuno's city came along.  In his downtown tile, Sims would drive by perfectly good jobs on the expressway and continue to the next tile when Simulator Z was run, but they'd get off the expressway and go to the jobs when Simulator A was run.

At first, this made no sense at all, and some quick experiments showed that the problem was not caused by differences in simulator capacities or maximum commute times.  This situation also seemed to completely disprove the theory that Sims would automatically go to the closest appropriate jobs.  Clearly, in Simulator Z, they weren't.  There was clearly something in the two simulators that was causing the different behavior.  It was if there were a parameter called Nearest Destination Attractiveness that was set much higher in Simulator A than in Simulator Z.

Well, that's exactly what turned out to be the case.  And when I had sumwonyuno triple the value of Nearest Destination Attractiveness in Simulator Z so that it matched the setting in Simulator A, large numbers of Sims started getting off the highway and going to the local jobs.

Well, that was easy.  Case solved, right?

Actually, no.  :(  In fact, this whole situation now looked like the worst mess possible.  :'(

Why, you might ask?  Well, when I asked sumwonyuno to triple the value of Nearest Destination Attractiveness, what I actually said was this:

Quote
Could you please take Simulator Z (Low) and change the pathfinding heuristic property from .003 to .009, and then see how it works in downtown Capitalis?

Those of you familiar with the traffic simulator may be aware of the Pathfinding Heuristic property, but see no property named Nearest Destination Attractiveness.  Others may see a property named Nearest Destination Attractiveness, and have assumed (as I did) that that was just another name for the Pathfinding Heuristic.

But it's not.  If you look at its name, it doesn't sound at all like what the PH does.  In fact, it does what I just described above.  Unfortunately, it's not a separate parameter.  Nearest Destination Attractiveness and Pathfinding Heuristic are two variables overloaded into the same parameter.  :'(  So when you lower the PH, which should always be safe, you also lower the Nearest Destination Attractiveness, which can cause the problem that sumwonyuno experienced.

Why did Maxis do this?  The basic logic is not hard to understand, given that the original game operates with a PH of .09.  With a PH that high, on a built-up large tile the Sims are lucky to find their way out the front door, much less find a job.  So Maxis apparently said, "OK, we'll make it so that the higher the PH, the closer to home the Sims will look for a job.  That way, they'll have a decent chance of finding one."  There's nothing wrong with that strategy, except that they overloaded these two very different variables into the same parameter.  Overloading variables is generally dicey at best, but this is one case where you don't want to do it.  Unfortunately, we're stuck with the result.

So what to do now?  I had sumwonyuno perform a few other tests, which also gave very strange results, but which indicated that there's even more going on here that we don't know about.  There's some hope that by adjusting other parameters in the simulator, the effect that sumwonyuno is seeing can be counteracted.  But it's going to take a fair amount of testing to see.  For the sake of efficiency, I've asked sumwonyuno to mail me a copy of his region and its plugins, and he's agreed.  I'll let everybody know what I find out.

In the mean time, what does this mean for other Simulator Z users, as well as for the proper setting of the PH?  For now, it appears to mean very little, if anything, for most people.  The situation in sumwonyuno's city is extremely anomalous; I've never seen or heard of anything like it before.  If other people have a situation similar to this, please let me know.  Otherwise, I wouldn't worry about it for now.  In general, the benefits of a lower PH still vastly outweigh this one anomaly, and I will be explaining new benefits that I've discovered in a post that will be coming soon.



At this point, I would like to mention that due to my RL situation, I am going to have to be cutting back a fair amount on my participation here.  I'll still be participating regularly, but it will be a little less frequently.  So if I don't respond to some posts or PMs immediately, that's why; responses will be coming, but they may just be a little slow.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on November 25, 2009, 02:03:17 AM
Quote
If other people have a situation similar to this, please let me know.

I use Simulator Z medium, and I've noticed some strange anomalies occurring in my cities with regards to pathfinding. I have no idea why this behaviour is occurring...

1. I've got a farm that sends freight right through the centre of town, completely ignoring a connection to an adjacent city tile which is both shorter and quicker. For some reason, this farm chooses to use the more heavily trafficked route to get its freight out to the next city tile. Both possible routes are road. This is an old picture, however even though the city is now significantly larger, that farm still uses that route. The connection that the farm is completely avoiding is used normally otherwise by other freight coming from other farms in the area. Why would freight go such a long distance across the tile when there is a far superior option available?

(http://img265.imageshack.us/img265/3951/freightoddity.jpg)

2. In the adjacent city tile, I have sims getting on a train from the border, getting off at a train station right in the centre of the town in that city tile (which is some distance away, about 30 tiles as the crow flies)... then they all get on a bus then head back to the same city tile they were heading from, except through a different road connection that is some distance away. Both connections are actually close to the centre of the map. Also, the pathfinding tool is a little screwy on that section of rail: it sometimes reads zero people using that track, even though the station records usage. Is this a case of the 'eternal commuter', or is it something more sinister? This problem is very erratic, sometimes it happens, sometimes it doesn't.

3. Ferries. I have a case of ferries disappearing into the next tile where there is no safe connection (as far as visuals go and as pathing goes) between the border of the adjacent tile and a ferry station. In other words, there is a point where the ferry has to go over land to reach its destination. Also, it isn't recorded on the ferry volume data view in the adjacent city tile. So basically... commuters are disappearing, and I have no idea why.

4. I have had cases where the simulator will actually rather use a street (going the longer way) even though the street which formerly had all traffic using it was upgraded to a road. These problems were quickly fixed by severing the offending street into two.

The towns in question have a very complex street network, however curiously there is no abandonment at all (apart from farms due to air pollution, too much traffic).

Other than these anomalies, Simulator Z has worked quite well.

If you need more pictures, please ask.
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 25, 2009, 02:49:29 AM
Interesting reading, Steve! :)


2. In the adjacent city tile, I have sims getting on a train from the border, getting off at a train station right in the centre of the town in that city tile (which is some distance away, about 30 tiles as the crow flies)... then they all get on a bus then head back to the same city tile they were heading from, except through a different road connection that is some distance away. Both connections are actually close to the centre of the map. Also, the pathfinding tool is a little screwy on that section of rail: it sometimes reads zero people using that track, even though the station records usage. Is this a case of the 'eternal commuter', or is it something more sinister?

Yes, it very much sounds like being the same as an eternal commute loop.
What happens to those sims when they re-enter the city they orginated from?


3. Ferries. I have a case of ferries disappearing into the next tile where there is no safe connection (as far as visuals go and as pathing goes) between the border of the adjacent tile and a ferry station. In other words, there is a point where the ferry has to go over land to reach its destination. Also, it isn't recorded on the ferry volume data view in the adjacent city tile. So basically... commuters are disappearing, and I have no idea why.

Obviously it's enough if the first city knows there's water and a ferry port in the neighbouring city.
Since the path in that city isn't known to the first city, it cannot take into account the fact the the ferry would have to cross land...
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on November 25, 2009, 03:09:31 AM
Quote
Obviously it's enough if the first city knows there's water and a ferry port in the neighbouring city.
Since the path in that city isn't known to the first city, it cannot take into account the fact the the ferry would have to cross land...

That's what I was thinking... but I wasn't sure. It's a bit weird to me, since I've never used ferries before.

Quote
Yes, it very much sounds like being the same as an eternal commute loop.
What happens to those sims when they re-enter the city they orginated from?

They don't reappear back in the city tile. It's really bizarre.
Title: Re: Traffic Simulator Z Development
Post by: z on November 25, 2009, 03:12:59 AM
1. I've got a farm that sends freight right through the centre of town, completely ignoring a connection to an adjacent city tile which is both shorter and quicker.

This looks suspiciously like the type of problem that sumwonyuno has been experiencing, in that it could be a case of Nearest Destination Attractiveness being set too low.  Could you please try changing this parameter (or Pathfinding Heuristic, as it is more often named) from .003 to .009, run your city for a couple of years, and see if the route changes?  If not, could you exit your city without saving, run Simulator A on it for a couple of years, and see if that changes the route?

Quote
2. In the adjacent city tile, I have sims getting on a train from the border, getting off at a train station right in the centre of the town in that city tile (which is some distance away, about 30 tiles as the crow flies)... then they all get on a bus then head back to the same city tile they were heading from, except through a different road connection that is some distance away. Both connections are actually close to the centre of the map. Also, the pathfinding tool is a little screwy on that section of rail: it sometimes reads zero people using that track, even though the station records usage. Is this a case of the 'eternal commuter', or is it something more sinister? This problem is very erratic, sometimes it happens, sometimes it doesn't.

Having read Tage's reply and your response, pictures would be helpful for this problem.  Also, following the steps I outlined for #1 would be very helpful here too.

Quote
3. Ferries. I have a case of ferries disappearing into the next tile where there is no safe connection (as far as visuals go and as pathing goes) between the border of the adjacent tile and a ferry station. In other words, there is a point where the ferry has to go over land to reach its destination. Also, it isn't recorded on the ferry volume data view in the adjacent city tile. So basically... commuters are disappearing, and I have no idea why.

I see that Tage has answered this one, and I agree with his answer.

Quote
4. I have had cases where the simulator will actually rather use a street (going the longer way) even though the street which formerly had all traffic using it was upgraded to a road. These problems were quickly fixed by severing the offending street into two.

How long did you let the game run after upgraded the street to a road?  It can sometimes take between five to eight years for a major change to be fully propagated, even though traffic will start appearing on the road relatively quickly.

Title: Re: Traffic Simulator Z Development
Post by: ldog on November 25, 2009, 11:07:22 AM
Very interesting. It does clarify some of the nagging suspicions that I've had for some time.

If you care to send the files to me as well I will be happy to assist in nailing this down.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 25, 2009, 01:30:09 PM
ldog,

Do you mean my files?

I'll be going to the post office in an hour or two to mail z the DVD he asked for.  Within the next few days I'll be redoing my plugins folder in preparation for my plans for my mayor diary (creating custom content and rebuilding the region).  I'll have backups of the region and plugins folder as it is right now.

[EDIT]:  All right, I'll be sending both of your copies sometime this afternoon.
Title: Re: Traffic Simulator Z Development
Post by: z on November 25, 2009, 02:33:25 PM
[EDIT]:  All right, I'll be sending both of your copies sometime this afternoon.

That sounds good to me.  I think there's a wealth of information here, and the more people working on it, the better.
Title: Re: Traffic Simulator Z Development
Post by: sumwonyuno on November 25, 2009, 04:38:43 PM
All right, the DVDs are sent and they should reach your respective homes sometime after Thanksgiving (December?).  If anything's wrong with them (blank, unreadable, broken, MIA).. well we'll see in a few days.  You guys are welcome to do whatever you want with the region (except say it's your own!  $%Grinno$%).  In a couple city tiles I had to do things to get a certain visual effect.  You may have to demolish some plopped buildings here and there, and activate cheats.  However, those things won't probably affect the results of the testing.

Now, variables overloading the same parameter?!  I've never heard such a thing...  &sly

So, for a lower pathfinding heuristic (better pathfinding), the closest (appropriate and available) job isn't so attractive; the higher the pathfinding heuristic (less desired pathfinding), the closest (appropriate and available) jobs is very much attractive.  Hmm, you guys may want to check East Capitalis.  A large chunk of commuters aren't going west to Downtown, but are going to suburban city tiles or going east to nowhere.
Title: Re: Traffic Simulator Z Development
Post by: z on November 27, 2009, 12:32:16 AM
I've recently been looking more closely into the requirements for RHW and NWM compatibility for traffic simulators.  In general, I think that the current settings of Simulator Z are fine here, but there's one area in which I'd like to make a somewhat significant change, and I'd like to get some feedback before I do.

One of the requirements for NWM compatibility is that the capacities and speeds per tile of roads, one-way roads, and avenues all be the same.  Not knowing how NWM was implemented, I simply have gone along with these requirements up until now.  But taking a closer way that one-way roads are used, both by themselves and in NWM, I want to question that particular restriction, and possibly change its implementation in Simulator Z.

In NWM, one-way roads are used only as part of the one-way road extensions; they are never used as part of two-way avenues.  So any changes to one-way roads would affect only the one-way thoroughfares in NWM.  So the question arises:  Do these really need to be the same speed and capacity of roads and avenues?  If not, what should their speed and capacity be?

In the original Maxis simulator, the speed of one-way roads was identical to that of regular roads, but their capacity was doubled.  These ratios hold true in Simulators C, D, and E as well, where all network capacities are multiples of the original Maxis capacities, and the speeds are the same.  There is a great advantage to using one-way roads in these simulators.  In Simulators A, B, and Z, the capacities and speeds of one-way roads are the same as regular roads.  Nevertheless, due to the asymmetry between morning and evening commutes over various routes, and the fact that congestion is calculated on a whole-day basis, there is a slight advantage to using one-way roads in SC4.  My observations have shown that that advantage will range somewhere from 0% to 20%.  In practice, this is barely enough to notice, and I have received numerous complaints that one-way roads are now almost useless, and not worth the trouble of building.  To be honest, my experience supports this point of view.

What does traffic engineering say about the speeds and capacities of one-way roads?  The few sources I have been able to find agree on a single number:  that the capacity and effective speed of one-way roads is in general two-thirds higher than that of equivalent two-way roads.

That's a big difference from the current state of things.  How does this compare to what we can observe?  First, a basic principle of traffic engineering (and actually of physics) is that for comparable roadways, capacity is proportional to speed.  If you double the speed of traffic on a road, then the road's capacity - the number of cars passing over a given spot per unit of time - also doubles.

Next, let's look at some RL examples.  For example, here in beautiful Eugene, Oregon, which is a small city of about 150,000, there are a number of one-way roads and also wide one-way roads that travel across town.  There are 11th and 13th Avenues, which are two-lane, one-way roads, and then there are 6th and 7th Avenues, which are four-lane, one-way roads.  Speeds and capacities on these roads are basically the same.  Especially near the downtown area, there are stoplights at virtually every block, although these thin out the farther away from downtown you get.  And like most major one-way roads, the stoplights are timed to the speed limit.  On any one of these roads, once I pass an intersection with a green light, I can set my car's cruise control to 30 mph and ride straight through to the end of the one-way road, right through all the stoplights, unless the road is heavily congested.

Contrast this with the two-way, two-lane roads that go through the busier part of town, which is where the one-way roads are.  There is no way to sync stoplights for two-way roads, so where there are a lot of them, you have to stop frequently.  At other intersections, there are stop signs.  And even for major two-way roads without stop signs, there is generally one lane in each direction (as in SC4), and traffic turning both on and off the road tends to slow the road down considerably.  For example, traffic on Willamette, which is one of the main roads in Eugene, tends to travel much slower than traffic on the one-way roads I mentioned, even over those sections where there are no stoplights.  Overall, it's easy to see in this town how the two-thirds speed and capacity rule applies.

What about big cities?  An excellent example is the biggest city in the U.S., New York - specifically Manhattan.  There's a saying in New York something to the effect that, "You can go uptown, and you can go downtown, but you can't go crosstown."  At first, this may seem a little strange, as Manhattan is a narrow island, and crosstown is the shortest trip you can make.  But Manhattan has many big, wide one-way avenues going uptown and downtown, while the major crosstown avenues are two-way, even though they have the same number of lanes as the one-way roads.  It is not unusual for the wide one-way avenues to carry traffic at several times the speed of the two-way avenues (technically they're called streets), even though the nominal speed limits are the same.  And the East Side avenues are efficient enough at carrying traffic that unless you're traveling more than a few dozen blocks, it's really no faster to go over a few blocks to FDR Drive, a major highway that parallels the avenues.

Some may say that one-way NWMs shouldn't have a significant speed or capacity advantage over avenues.  But in the real world, they do.  Look at Manhattan again.  On the Upper West Side, Broadway, which is a four-lane, two-way avenue, parallels Amsterdam and Columbus, which are wide one-way avenues.  Anyone who wants to travel more than a few blocks by car will take Amsterdam or Columbus, as they are much faster than Broadway, even though the speed limit is the same.  So for all these reasons, I don't think that raising the speed and capacity of one-way roads by a realistic amount makes a traffic simulator not compatible with the NWM.  To the contrary, I think such a change makes it more compatible.

What about all the side streets in Manhattan that are one-way?  They don't have the advantage of timed lights, and their speed and capacity is about the same as normal streets.  Recently, a proposal has been made for one-way streets in SC4.  I think this is great idea, as they would have the same capacity and speed as regular streets, and would provide a nice alternative to higher-capacity one-way roads.

Speaking of alternatives, boosting the speed and capacity of one-way roads would have yet another benefit.  A long-standing complaint in SC4 is that all roads and avenues have the same speed limit.  If one-way roads have a higher, more realistic speed limit, then players can immediately construct their own higher-speed avenues.  Eventually, higher-speed forms of NWM could be made this way.  I believe that higher-speed two-way roads could also be made using the one-way network; someone with more knowledge of this process can confirm or deny this.  Assuming they could, they would serve as an excellent intermediate between standards roads and RHW-2.  And unlike RHW-2, residences and businesses could be built right up against them.

I mentioned earlier that one-way roads are considered to give a two-thirds boost to capacity and speed, and I also mentioned that the current setup for Simulators A, B, and Z gives a boost of from 0% to 20%.  I am proposing to increase the speed and capacity of one-way roads to be 50% higher than that of regular roads, which should make them come out about right.  As I mentioned, this will immediately make faster hand-made avenues possible, while leaving regular avenues unchanged.  What do people think about this proposal?  If there is enough popular response, I can post a full release of Simulator Z with these changes in this thread within the next couple of days.
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 27, 2009, 05:51:14 AM
OK,

     Thanks a lot Steve for looking into this .. also your earlier posting on " nearest Destination Attractiveness"
parameter was flat out amazing  &apls ..And you are really unravelling the mysteries which surround understand
the traffic sim !

     I like what you said here, and ive thought about OWR's in the same ways you have at times..
But I was thinking the 50 % speed bonus to them over roads was just a bit too high.. I would say
the speed bonus should fall some where between 20 - 50 % , but not sure of an exact figure...

Id like to hear what others want with this ?

Brian
Title: Re: Traffic Simulator Z Development
Post by: gottago on November 27, 2009, 06:31:32 AM
I'll admit I've been lurking on the traffic sim development threads for a while now and following the discussions--great work going on here.

Z, re: your post on OWR,  I'd heartily endorse the 50% higher speed and am frankly surprised that there is no current advantage to them, as there obviously should be, and as you detail from RL examples and stats. And 50% seems entirely reasonable considering the advantages they offer in terms of the greatly increased capacity (or to borrow a term, "throughput") they offer, which you note must be defined in terms of speed.

Edit to add: this might be a good subject for posting a general poll for wider feedback.
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 27, 2009, 07:39:57 AM
I am proposing to increase the speed and capacity of one-way roads to be 50% higher than that of regular roads, which should make them come out about right.

Every time the network speeds have been tweaked, they've been increased... ::)
How about this time lowering the speeds of roads and avenues instead?

On the other hand, I would also want to hear from Alex if and how this would affect the NWM... ;)
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 27, 2009, 10:01:21 AM
Every time the network speeds have been tweaked, they've been increased... ::)
How about this time lowering the speeds of roads and avenues instead?
Faster! Faster! Faster! We all wanna go faster!

I'd just change the cap and leave the speeds alone. The lessened congestion will provide enough speed advantage.

50% on the cap sounds about right. Since I've been testing mostly with stock caps lately, I do think the 100% increase Maxis used is a wee bit much.
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 27, 2009, 11:09:57 AM
Faster! Faster! Faster! We all wanna go faster!

 :D  Yeah, I know... ::)

Read this post (http://sc4devotion.com/forums/index.php?topic=6726.msg214642#msg214642) and the rest of that thread... :)
Title: Re: Traffic Simulator Z Development
Post by: z on November 27, 2009, 03:11:25 PM
Every time the network speeds have been tweaked, they've been increased... ::)

Not true.  The most recent version of Simulator Z reduced rail speeds by 20% to 30%, with the biggest reductions coming in the heaviest used rails - subways, el rail, and commuter rail.  All of these are now significantly lower than the original Maxis speeds.  The monorail is now equal to the original Maxis speed; I can't really drop it any lower since it serves HSR and BTM as well.  Also, roads and avenues are currently 10 kph lower than in Simulator A.  There are no plans to raise any other speeds.

I'd just change the cap and leave the speeds alone. The lessened congestion will provide enough speed advantage.

Speed and capacity go together for similar networks.  Not only is this a basic law of traffic engineering and physics, as mentioned in my original post, but it's reflected in the highways and RHW as well.

Quote
How about this time lowering the speeds of roads and avenues instead?

See the reference to your post below...

Quote
On the other hand, I would also want to hear from Alex if and how this would affect the NWM... ;)

I would as well.  That's one of the reasons I put in a detailed analysis of his home town.  But this proposal has been made in light of information I received from him recently about the workings of NWM.  Alex has already said that he thought that some increase in the one-way road capacities and speeds would be OK for NWM; the question at this point is how much.  I have tried to propose a realistic amount, and there will be plenty of time to discuss it and test it.

Read this post (http://sc4devotion.com/forums/index.php?topic=6726.msg214642#msg214642) and the rest of that thread... :)

Yes, I've been thinking a lot about that post since it was made.  Basically, one of the points you make is that you get better mass transit usage with a wider spread of vehicle speeds, which is true.  But Simulator Z was starting to suffer from too much MT usage; this was a result of using Perfect Pathfinding.  I was getting complaints about roads being almost deserted, and not enough customers for businesses.  Hence the speed reduction, and people seem uniformly happy with the results.  Speeds are now pretty realistic (at least in terms of top speed) across the board.  I think that this was Maxis' original intent, but it had to spread the speeds out when it raised the PH to .09.  The changes I'm proposing to one-way roads simply bring realistic behavior to the one part of speeds and capacity where it has been sorely lacking.  Extensive testing has shown that the rest of the current speed structure works well for the simulator.  Lowering road and avenue speeds, as you suggested above, would bring back the car usage and business customer problems.
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 27, 2009, 05:34:55 PM
Speed and capacity go together for similar networks.  Not only is this a basic law of traffic engineering and physics, as mentioned in my original post, but it's reflected in the highways and RHW as well.

And if this were reality that would be true. One big difference between the traffic simulator and reality; each run of the traffic simulator is a snapshot of a single point in time. So raising the speed only raises the amount of cars passing through because it makes the route more attractive to the pathfinder. Congestion has a pretty big effect on speed. Network capacity has a pretty big effect on congestion. So while the effect of changing the capacity is not 1:1 or even anything close, raising or lowering capacity from a gameplay view has a similar effect to raising or lowering speed; provided there is enough traffic to make a difference.

The important thing is that the (pair of) owr needs some kind of advantage over the (pair of) regular road or there is no point in using it. On the other hand a pair of  owr should not >= to an ave, but I think there is room to play around with in between. And of course they cannot be so superior to a road that there is no longer any point in using the road either (original streets were a good example of worthlessness).

So do what you want, it is going to work fine either way.
Title: Re: Traffic Simulator Z Development
Post by: Tarkus on November 27, 2009, 09:54:44 PM
But this proposal has been made in light of information I received from him recently about the workings of NWM.  Alex has already said that he thought that some increase in the one-way road capacities and speeds would be OK for NWM; the question at this point is how much.  I have tried to propose a realistic amount, and there will be plenty of time to discuss it and test it.

As I recall from the early discussions on "NWM compatibility", the reason we went for the equalization was necessitated as a side-effect of the more critical Road/Avenue equalization.  Without it, the "fake OWR-based 2-way Avenues" that some people have built would gain an advantage over the Avenue and the multi-tile 2-way NWM networks (an idea which you've addressed later in your post, which I'll touch on as well).  Personally, I think 50% may be a bit much, and somewhere in the 10-25% range is perhaps more appropriate.  That would still work out to about a 50% increase in capacity on 2-tile one-way networks.  It's too bad we can't set Intersection and Turn Capacity values separately by network, as most of the benefit of OWRs seems to come at intersections, due to fewer conflict points and the effect of the green wave (http://en.wikipedia.org/wiki/Green_wave) (which is definitely in full force on the 11th/13th couplet in Eugene).

Speaking of alternatives, boosting the speed and capacity of one-way roads would have yet another benefit.  A long-standing complaint in SC4 is that all roads and avenues have the same speed limit.  If one-way roads have a higher, more realistic speed limit, then players can immediately construct their own higher-speed avenues.  Eventually, higher-speed forms of NWM could be made this way.  I believe that higher-speed two-way roads could also be made using the one-way network; someone with more knowledge of this process can confirm or deny this.  Assuming they could, they would serve as an excellent intermediate between standards roads and RHW-2.  And unlike RHW-2, residences and businesses could be built right up against them.

I mentioned earlier that one-way roads are considered to give a two-thirds boost to capacity and speed, and I also mentioned that the current setup for Simulators A, B, and Z gives a boost of from 0% to 20%.  I am proposing to increase the speed and capacity of one-way roads to be 50% higher than that of regular roads, which should make them come out about right.  As I mentioned, this will immediately make faster hand-made avenues possible, while leaving regular avenues unchanged.  What do people think about this proposal?  If there is enough popular response, I can post a full release of Simulator Z with these changes in this thread within the next couple of days.

Unfortunately, the problem with the One-Way Road network is that Maxis hardcoded a virtually irreversible "tidal flow" effect in terms of how that network handles path files.  The path file for the orthogonal OWR (0x09004b00) is identical to the path for orthogonal Road (0x00004b00), and at first glance, it looks like it is pathed for 2-way traffic.  However, when an OWR is built, the game effectively forces the "wrong way path" to go the "correct" way.  There are some rare occasions where a special "crossover path" can counter the flow (something I discovered by accident), but that effect wouldn't help here.  In essence, while it is possible to create a 1-way network out of a 2-way network (see the RHW), it does not appear to be possible to create a 2-way network out of a 1-way network.

Further, the way the OWR network relates its directionality to the RULs, when an OWR's direction is reversed, the network textures (or models) are not rotated, making it impossible to tell which direction an OWR is going from the RUL end.  This is part of the reason the traffic signal T21s on the OWR network are so skimpy (that and the lack of functional stop points). 

In all honesty, I think it'd be easier to turn the Avenue into a 1-tile network than to get the OWR network to accept 2-way traffic. ::)  Though that would open a whole other can of worms.  (And as Vince recently discovered, you can do some pretty wild stuff with median flags.)

Title: Re: Traffic Simulator Z Development
Post by: z on November 28, 2009, 12:31:56 AM
I appreciate everybody's input here.  It sounds like there is a consensus that one-way roads could use some beefing up; it's just a question of how much is appropriate.  In the real world, they make a big difference in traffic flow, although drivers may need to take slightly longer routes as a result.  I think it would be good to see the same general results in SC4, as long as we can do so without causing unwanted side effects.

I'd like to address a couple of the points that Alex raised:

Quote
  It's too bad we can't set Intersection and Turn Capacity values separately by network, as most of the benefit of OWRs seems to come at intersections, due to fewer conflict points and the effect of the green wave (http://en.wikipedia.org/wiki/Green_wave) (which is definitely in full force on the 11th/13th couplet in Eugene).

I agree completely.  It's because we can't simulate either of these effects properly in SC4 that increasing the capacity and speed seems appropriate, as the same effect is accomplished through different means.

Quote
In essence, while it is possible to create a 1-way network out of a 2-way network (see the RHW), it does not appear to be possible to create a 2-way network out of a 1-way network.

That's too bad; I was hoping this could be done.

Quote
In all honesty, I think it'd be easier to turn the Avenue into a 1-tile network than to get the OWR network to accept 2-way traffic. ::)  Though that would open a whole other can of worms.

It sounds like it would be best to pass on that.  I think we've got enough worms for now...  ::)

Personally, I think 50% may be a bit much, and somewhere in the 10-25% range is perhaps more appropriate.  That would still work out to about a 50% increase in capacity on 2-tile one-way networks.

From my own observations, as well as those I received from other users (which were all in the form of complaints about the current state of one-way roads), I think this overestimates the intrinsic advantage of one-way roads over two-way roads in SC4 by a fair amount.  I'd like to make a slightly different proposal here.  Instead of a 50% increase, let's try a 40% increase in an open beta.  On one hand, we can be rather sure that the results will not exceed the two-thirds premium that is standard in the real world, and what we should see should usually be less.  Yet 40% is certainly high enough to make a significant difference from the current state.

As far as hand-built avenues go, these would have a 40% premium over regular avenues as well as NWM two-way avenues.  The intrinsic difference between one-way and two-way roads does not come into play here.  Having a four-lane avenue with a speed limit 40% higher than a standard avenue is certainly quite common, especially in suburban areas; I think it would be a useful and welcome addition to SC4.  On the other hand, very wide avenues such as those in the coming NWM are typically found in more built-up parts of the city where there is enough traffic to require them, and in these areas the speed limits tend to be the same as roads.

So that's my proposal; we can try it out in beta form and see how it works.  What do people think about this?
Title: Re: Traffic Simulator Z Development
Post by: b22rian on November 28, 2009, 05:33:09 AM


From my own observations, as well as those I received from other users (which were all in the form of complaints about the current state of one-way roads), I think this overestimates the intrinsic advantage of one-way roads over two-way roads in SC4 by a fair amount.  I'd like to make a slightly different proposal here.  Instead of a 50% increase, let's try a 40% increase in an open beta.  On one hand, we can be rather sure that the results will not exceed the two-thirds premium that is standard in the real world, and what we should see should usually be less.  Yet 40% is certainly high enough to make a significant difference from the current state.

As far as hand-built avenues go, these would have a 40% premium over regular avenues as well as NWM two-way avenues.  The intrinsic difference between one-way and two-way roads does not come into play here.  Having a four-lane avenue with a speed limit 40% higher than a standard avenue is certainly quite common, especially in suburban areas; I think it would be a useful and welcome addition to SC4.  On the other hand, very wide avenues such as those in the coming NWM are typically found in more built-up parts of the city where there is enough traffic to require them, and in these areas the speed limits tend to be the same as roads.

So that's my proposal; we can try it out in beta form and see how it works.  What do people think about this?


    Sure Steve , it sounds like a great idea to me to do a Beta first.. That way hopefully you can get plenty of
feedback from users as to how they like it and it affects their transit systems.. Just off the top of my head it
sounds maybe a little on the high side to me ( course maybe as its not been tested yet..) but I think I could live
with 40 %, if thats what it ends up being in the end.. I know i said a big range 20-50 %.. But after reading
 alex's post above.. now im thinking more on the lower end of that range.. Of course we can just as easily end
up testing other values such as 30 % and 20 % later on also, and im sure we will.

Thanks, Brian
Title: Re: Traffic Simulator Z Development
Post by: RippleJet on November 28, 2009, 07:15:37 AM
I'd be careful with overshooting too much, and would thus suggest no more than 30% in the first test.
It's always easier to increase it in a second beta test (if needed) than to lower it... ::)

30% would be roughly the same speed advantage Maxis gave to avenues over roads and owr's.
With a PH lower than 0.09, the advantage would anyways be bigger than that provided by Maxis for avenues.
Title: Re: Traffic Simulator Z Development
Post by: tamorr on November 28, 2009, 12:10:32 PM
  I personally welcome the increase in advantage, even though I am not able to do any testing, I would prefer there be said advantage, if only for OWRs... As that is a network down in such a way to counter the effects of roads becoming too much to handle. Well the is my take on it....


I would have to agree with RippleJet in that it is better to raise a value in small incriments than it is to lower said value. Makes things a bit more like the smoothing into what can be donate of the value that is being looked for. Ease into that which is sought out. Step by step we'll get there with a basis to be set... So I'd say starting at 30% would be best and increasing from there as said. :)
Title: Re: Traffic Simulator Z Development
Post by: z on November 28, 2009, 04:27:09 PM
As people generally know, I like to have as accurate a simulation as possible.  (I'm understanding my CML of "Detailman!" more all the time.)  At the same time, making users happy is at least as important.  So in light of recent feedback here, I decided to do some more research on one-way road capacities and effective speeds.  On one hand, I found quotes such as the following from the article Should Cities Convert One-Way Streets to Two Way? (http://www.ti.org/vaupdate30.html)

Quote
"You need seven lanes of a two-way arterial to achieve the same capacity as four lanes of a one-way couplet," says transportation planner Michael Cunneen.

This would imply a 75% capacity and effective speed advantage for one-way roads, even higher than the 67% I had seen cited elsewhere.

On the other hand, further research showed lower figures quoted.  In retrospect, it is easy to see why.  Not all one-way roads have synchronized traffic lights, and if the traffic lights and intersections are far enough apart on two-way roads, the difference between the two types of roads narrows.  So the 30% increase being discussed recently, when added to the intrinsic difference between one-way and two-way roads in SC4, is within the realm of realism, although it's a bit on the low side.  The 30% figure does make it even easier to justify alternative, high-speed avenues, though.  Whereas the standard avenue in Simulator Z has a speed of 50 kph (31 mph), a hand-built avenue using one-way roads would have a speed of 65 kph (40 mph), which is a very common speed for avenues outside city centers, at least in the U.S.

The way capacities are set in Simulator Z, it works out a bit better to increase them by a third, as it still leaves the simulator with nice round numbers.  My experience is that speed and capacity differences of less than 10% are not really noticeable by the user, and do not have a noticeable impact on the game.  And current Simulator Z capacities are not exactly proportional from one capacity level to another, so this would be nothing new.  To give a specific example, the road capacity for Simulator Z (Low) is 2400; increasing it by 30% gives 3120, while increasing it by a third gives 3200.  The difference of 80 between these two numbers is small enough to get lost in the noise.

So barring any major objections, those are the numbers I will use for the beta release.  The 30% number is certainly high enough to make a significant difference, but I wouldn't go any lower than that, at least for this beta release.  Comments are welcome.
Title: Re: Traffic Simulator Z Development
Post by: delta9 on November 28, 2009, 08:52:44 PM
Well, as a mathhead (that's an 'a', not an 'e' ;)) I'd say go with the 1/3 increase.  Rational multiples are always good  :D

I definitely agree that the OWRs should have the advantage for the reasons stated, for realism and gameplay's sake (one of the rare instances in which those two things overlap ::)), and agree completely with the resultant real/'fake' avenue speed difference.  For example, many of the well-traveled avenues in the north part of Austin such as Anderson Lane and Burnet Road are set at 30mph/~50kph (and are generally faced by CS$ to use SC4 terms ;D), while Lakeline Boulevard, the arterial avenue that serves a significant portion of residents in my northwestern suburb of Cedar Park, is set at 40-45mph/~65-70kph (and a red congestion view in Z Ultra :D).  There are plenty more examples of this around town and in other cities.  It would be a useful change, and would give me a reason to finally use Marrast's dividers that have just been festering in my plugins for so long $%Grinno$%

Of course, there's the whole scale thing that I think RippleJet/Tage (if I may) brought up, and if you, as you mentioned, developed a traffic sim around that, I'd be down for testing and whatever help I can provide (haven't done any hands-on modding yet but I have a good general understanding of the game's simulators and a bit of a background in programming).  The scale of the game has always been a nagging problem to me, from having 20+ people commute from a mansion to work, to having 40+ foot wide residential streets, 50 foot wide roads, 50 foot high embankments and bridges, etc...  If that's an idea you or anyone else would like to pursue further, you can rest assured that at least one person would use it ()stsfd()

EDIT: The scale issue wasn't brought up in here, but rather in this thread (http://sc4devotion.com/forums/index.php?topic=6726.msg214966#msg214966), as linked earlier.  But besides, I think the question of overall scale in the game should be based upon building footprint more than anything, and that's an entirely different topic, perhaps one to be pursued.  Back to traffic simulators...
Title: Release of Simulator Z V1.3 Beta 1
Post by: z on November 29, 2009, 01:27:02 AM
I've attached the Beta 1 release of Simulator Z v1.3 at the end of this post.  It contains the settings for one-way roads discussed in my previous post.  This is not a final release, so it can always be changed, but based on the discussion here, it sounds very likely that these will be the final numbers.  I've also included Simulator Z Classic, which is now a standard part of the Simulator Z release.  As per an earlier discussion with Alex, I've taken his suggestion for selecting a slightly higher avenue capacity and speed for this one version of the simulator, so that it fulfills the goal I had of more closely matching the original Maxis simulator.  Standard avenue capacities and speeds are unchanged in the other versions of Simulator Z.

Along with the revised version of Simulator Z Classic, for the first time I'm enclosing a Traffic Volume Data View designed specifically for Simulator Z Classic.  While constructing this new Traffic Volume Data View, I found a bug in the standard Traffic Volume Data View, which is used with the standard Maxis simulator; I've enclosed a corrected version of this data view for those who are interested.  Final versions of all of these files should be released with the next NAM.
Title: Re: Traffic Simulator Z Development
Post by: Shadow Assassin on November 29, 2009, 03:29:17 PM
Hey, z, sorry for the late reply...

This looks suspiciously like the type of problem that sumwonyuno has been experiencing, in that it could be a case of Nearest Destination Attractiveness being set too low.  Could you please try changing this parameter (or Pathfinding Heuristic, as it is more often named) from .003 to .009, run your city for a couple of years, and see if the route changes?  If not, could you exit your city without saving, run Simulator A on it for a couple of years, and see if that changes the route?

I haven't had time to test this problem yet - but it does not seem to affect overall running of the city.

Having read Tage's reply and your response, pictures would be helpful for this problem.  Also, following the steps I outlined for #1 would be very helpful here too.

I see that Tage has answered this one, and I agree with his answer.

I haven't gone into that city tile since I asked about it - but the problem solved itself after upgrading a segment of street to road the last time I played the tile. Now only buses still remain (which are all coming from houses bus stops within the city tile now, rather than the rail station, as previously).

How long did you let the game run after upgraded the street to a road?  It can sometimes take between five to eight years for a major change to be fully propagated, even though traffic will start appearing on the road relatively quickly.

The game ran for about two years, but as time progressed the changes ultimately were successful. Now I have to upgrade that road to an avenue...

Anyway, just an enquiry: when I had two "towns", on both sides of a city tile, rolling Non-Job-Zots occured in some parts of town when I upgraded the ferry pontoon on the south side to a car ferry, and created a new car ferry on the north side. These non-job-zots went away when I created a road bridge further upstream. Abandonment was due to "commute time". The average commute time dropped from about 60 to less than 30, then the simulator fixed everything after five years or so of game time. Is this normal behaviour for when such a large infrastructure upgrade is undertaken?

It's just an enquiry - there is no problem otherwise.


Also - I'm having trouble seeing where existing bus stations are on the data view... I recall a mod of tropod's that showed bus stations on the relevant volume data view as bright green compared to the usual blue of the default view... is something like this available on the modified volume views? It would be exceedingly handy for making sure that areas aren't doubled-up, particularly with how well RTMT blends in with normal street furniture, just like it should in real life.
Title: Release of Simulator Z V1.3 Beta 2
Post by: z on November 30, 2009, 01:38:06 AM
The Streets of Sim City

[First, thanks for your post, Shadow Assassin - I'll get back with a reply soon.]

So far, testing of the one-way roads has been giving results about what I expected - the changes have a definite positive impact, although I think they're a bit on the low side.  I will be very interested to hear from other people what they think of these changes, and whether they should be adjusted further.  But overall, I think that this is a positive development in adding flexibility to existing networks.

Along those lines, I started looking more closely at the street network.  Maxis always had an ambivalent attitude toward streets.  On one hand, they were highly integrated into the system; the game even creates them automatically when you zone large enough areas.  And if you turn all your streets into roads, you get complaints from the game.  Yet in the original game, the capacity of a street was a paltry 100.  This increased significantly in the 2x and 5x simulators, and Simulators A and B continued this increase by making street capacities a minimum of 1000, even for their Hard versions.  Until now, Simulator Z has had street capacities roughly comparable to Simulators A and B.

There's been a bit of a dilemma here in that we want to have streets have sufficient capacity to handle necessary traffic without getting unnecessarily congested, but at the same time we don't want to make them so attractive to traffic that they're used as major routes.  Some of the experiments I've recently performing and have documented in this thread point to a way where both of these goals can be accomplished without conflict.  With perfect pathfinding, such as used by Simulator Z, network speed becomes one of the biggest factors in determining which routes Sims will take; in many cases, speed becomes the determining factor.  Therefore, by maintaining an appropriate difference between the speeds of roads and streets, Sims will choose roads whenever it makes sense.  This being the case, it's possible to boost the capacity of streets without having a negative impact on the game.  Instead, doing so will simply lessen the congestion of streets, and greatly lessen the promptings of the advisor to upgrade them to roads.  However, simply increasing the capacity of streets will not in and of itself create more street traffic.

This raises the obvious question:  What's the proper capacity for streets?  What I keep running into as I tune the simulator is that ideally, capacity is proportional to speed.  Although as Lenny points out, the traffic simulator does not reflect reality in many ways, I have found that using this real world relationship does produce good results in the simulator.  So I've created new street capacities for Simulator Z by taking the road capacity and multiplying it by the ratio of street speed to road speed.  Additionally, I've made one change in street speeds; I've lowered the street speed for cars from 35 kph to 30 kph.  (Road speed is 50 kph.)  This was done for two reasons:  1) To bring it more in line with other street speeds compared to road speeds; and 2) to help ensure that the speeding premium, which may be as high as 30%, does not draw through traffic from adjoining roads.  As Sims have effectively unlimited commute time in Simulator Z, and we're trying to discourage them from using streets excessively anyway, this should have no negative effect on game performance.

Making street capacities proportional to road capacities makes a big difference, as there was very little relationship between them before.  The range of increases was from 50% for Simulator Z (Low) to 300% for Simulator Z (Ultra).  Simulator Z Classic was unchanged, as its purpose is to replicate the capacities of the original Maxis simulator.  But the changes in the other simulator versions should make it much easier to construct cities that use roads, avenues, and highways as main thoroughfares, and streets for everything else.  Usage of features such as SAM becomes much easier without running into problems from other parts of the game.  So please give this version of Simulator Z a try, and let me know what you think.  The attached package contains the same files as the Beta 1 version of Simulator Z v1.3, and includes the same changes to one-way roads.
Title: Re: Traffic Simulator Z Development
Post by: ldog on November 30, 2009, 01:44:45 PM
Really excellent thinking on the streets.  :thumbsup:
I've been wondering what to do with them myself.

About the avenues vs owr. Since the topic came up I've been observing them more closely myself.
I hadn't realized the capacity for ave and highway was per tile.
The ave really is a pair of owr. So equalizing them is not such a bad thing.
Being as the ave is a bit more expensive, just making it the "higher speed limit" equivalent of a pair of owr seems balanced enough.

All that being said I am completely ignorant of NWM needs, but in the end I hope you find values that work both with and without it.
Title: Re: Traffic Simulator Z Development
Post by: z on December 04, 2009, 05:57:15 PM
Challenge and the Traffic Simulator

Most people want their traffic simulator to provide at least some challenge to their game play, and of course different people desire different levels of challenge.  In order to pick a traffic simulator that supplies the proper amount of challenge for your city, it's necessary to understand what makes a traffic simulator challenging.  This is not as obvious as it may seem, which is why I'm making this post.

On one hand, the original Maxis traffic simulator could be seen as very challenging.  But it made it impossible to build large, healthy cities.  In such cities, one of the biggest problems was that a fair amount of residential abandonment due to commute time was unavoidable, even when there were suitable jobs within easy commuting distance for the Sims who eventually left the city.  So the type of challenge that makes it impossible to create a healthy city, no matter what you do, is not very desirable.  Being a little more specific, having abandonment due to commute time when appropriate jobs are within easy commuting distance is not desirable, because it is not something that can be fixed by the player, no matter what is done.  In the real world, some abandonment is normal, and as an extreme case, half the city of Detroit is currently abandoned.  Yet if you look at these real-world cases, all of this abandonment is due to lack of demand, not commute time.  SC4 has plenty of mechanisms that can result in abandonment due to lack of demand, which in those cases is quite appropriate.  So the traffic simulator doesn't need to add spurious abandonment here.  If there aren't proper jobs available to the residents, you might get abandonment due to commute time from the simulator, but that's a mislabeling; it's really abandonment due to lack of demand that's encountered by the traffic simulator instead of other parts of the game.  That type of abandonment is quite reasonable, especially since the player has the ability to take actions to fix it.

What other forms of challenge are there?  Obviously, there's traffic congestion, and in fact most of the other forms of challenge in the traffic simulator stem from congestion.  In Simulator Z, at first glance it seems that the only effect of congestion is to have yellow, orange, and red lines appear on your congestion data view.  And then there's what Lenny so colorfully described as "advisor spam":  Your transportation advisor constantly nags you about "Traffic Jam On Side Street Has Local Sims Stewing," or "Local Road Reaches Limit - A Chaos of Cars," or "Big-Time Traffic Problems Hit Local Avenue."  (Many long-time players have these messages burned into their brains.)  For many players, the combination of these two factors is enough of a challenge to encourage them to improve their transportation systems.  But in reality, a lot more is going on behind the scenes, and congestion is a lot more damaging to the city in all traffic simulators than it appears at first glance.  Understanding how this works can be very helpful in choosing a traffic simulator and in planning your city.

I described a lot of the effects of congestion in an earlier post, but that was a very long post, and the part about congestion may have gotten lost in it for many people.  So I am reproducing that part here (edited slightly), so that all the material regarding traffic simulator challenge can be found in a single place.  The part that I am reproducing is between the two solid lines, so if you did read this before, you can skip it now.



Excessive traffic congestion can result in an increase in noise levels that makes residential areas less desirable, an increase in pollution, and a decrease of up to 14 points from neutral in the local Mayor Rating, or much as a 28 decrease from optimal in the local Mayor Rating.  Furthermore, these effects all have side effects themselves.  For example the lower Mayor Rating can be a contributing cause to riots in your city; this effect has actually been observed in Simulator Z Classic, which has the very low network capacities of the original Maxis simulator.  If your congestion is widespread, this can have a significant effect on your global Mayor Rating, which affects which rewards you can get.  To quote the Prima Guide regarding the awards:

Quote
In addition... they improve your city in myriad other ways (enhancing desirability, boosting EQ or HQ, further increasing Mayor Rating, to name a few).

Note the last point.  This means that bad traffic can eventually cost you a lot more than 14 to 28 points in your Mayor Rating, ending up having a very major effect on the game, even with no abandonment due to commute time.  And abandonment due to demand may still happen, of course, and if you look at the above quote, you can see how bad traffic can start a cycle than can result in exactly that.  So depending on the level of congestion, any number of bad things can happen to your city.



There's one other important way that congestion can have a major effect on the difficulty of game play, and that's in commute time.  A lack of suitable transportation networks in a city may also cause the same problem, even if no congestion is present.  You may remember from earlier in this thread that in experiments to test the effect of the pathfinding heuristic, we found that in large cities, a higher pathfinding heuristic made the city less attractive to high-wealth Sims.  A short form of putting this causal relationship would be the following:

Pathfinding Heuristic => Desirability

We knew there had to be more intervening steps, but we didn't know what they were at the time.  I have since done some more research, and discovered the details of how this mechanism works.  It's not that much more complicated than the above statement, and can be stated as such:

Pathfinding Heuristic => Commute Time => Desirability

By definition, the higher the pathfinding heuristic, the higher the commute time.  Yet as I have stated many times, the maximum commute time in Simulator Z is effectively unlimited.  However, I'm sure you're all familiar with the short, medium, and long commute times that can be displayed when you query a residence.  And long commute times specifically reduce the desirability of the residences of the Sims who are commuting.  Reduced desirability in can be a big factor in why a building downgrades in wealth status.  So this is how a higher pathfinding heuristic can make a city less attractive to high-wealth Sims.

As for how this applies to congestion, congestion lengthens commute times.  Depending on the level of congestion, this can increase the number of long commute times a little or a lot.  When it increases them significantly, you get reduction in desirability, and you may start to see your high- and mid-wealth Sims leave town, replaced by low-wealth Sims.  On the other hand, a short commute time results in higher residential desirability, essentially helping to attract high-wealth Sims to your city.

So I hope I have shown that there is a lot more to the effects of traffic congestion than meets the eye, and I hope that this information will be useful in selecting a traffic simulator for your city that provides the level of challenge that you want.
Title: Re: Traffic Simulator Z Development and Theory
Post by: b22rian on December 05, 2009, 03:36:55 PM
very well written and quite informative..

I never really considered the relationship between congestion, longer commutes times
and desirability very closely..

thanks for this Steve  &apls

brian
Title: Re: Traffic Simulator Z Development and Theory
Post by: z on December 06, 2009, 03:30:15 AM
The Curious Case of Capitalis
- and -
More News on the Destination Finder

Regular readers of this thread may recall that last month, sumwonyuno posted a description of certain problems he was having with his region of Capitalis that appeared at the time to be related to Simulator Z.  At my request, he performed a number of tests, which produced some rather confusing results.  I then asked him to send me a copy of his city with its plugins so that I could do some more intensive testing here.  I have now done these tests, and I believe that the questions raised about Simulator Z have been answered.  I have also gained a bit of insight about what's actually happening in sumwonyuno's region.  Finally, this whole exercise has cast more light on how the Destination Finder works.

For those who like to know just the basics, I'll post a quick summary of my findings first, and then I'll post the details.  Here's the summary:

1. After extensive testing, I could find no evidence of any malfunction in Simulator Z.  Specifically, Perfect Pathfinding was not causing any problems, and was performing as expected and desired.  Simulator Z and Simulator A produced essentially identical results in all the cities I tested.  Although this is contrary to sumwonyuno's findings, I can show how the larger scope of my tests include his observations without contradiction.

2.  As you may gather from the previous point, there is no traffic simulator problem of any kind in the region.  Furthermore, the game appears to be operating properly.  The extent to which Capitalis behaves differently from the real region upon which it's based appears to be due solely to the fact that SC4 is not a perfect real-world simulator.  Within the rules of SC4, everything appears to be working properly.


When I received Capitalis from sumwonyuno, the Downtown city had been running Simulator A for some time.  I switched it to Simulator Z and ran it for 33 years, much longer than sumwonyuno's tests.  A summary of what I found can be seen in the following RCI graph:

(http://img46.imageshack.us/img46/9535/zhrci.jpg)

There is no significant change in any of the three populations over time.  If you just look at the graph, it's very hard to tell where I switched simulators.  The importance of this graph is that it shows that Sims had no more trouble getting to local jobs under Simulator Z than they did under Simulator A.  And as we saw when testing the pathfinding heuristic, some downgrading or abandonment would happen within a few years of using a higher PH, even if everything was running fine before.

But you might say, "Well, that's a different situation.  Here it's not the paths that are changing; it's the destinations."  There's an easy way to test that out.  I stop the game, find the local Sims going to local jobs, and in the middle of the night, I bulldoze their residences.  (Caught them Sims napping!  ;D)  Now there are no workers at those far-flung jobs.  What happens now?  Here's the answer:

(http://img189.imageshack.us/img189/4702/rebuildn.jpg)

Look at the point where the population takes a little plunge.  The job count doesn't even budge.  That's just what you would hope.  The Sims passing through town now see open jobs here, and take them instead of continuing to the next tile.  That's the only place those workers can be coming from.  Meanwhile, the population slowly edges back upward, but the jobs don't increase.  Why?  Tax rates for R$ and R$$ are set to zero here.  But the local jobs are filled to the point that they can be.  The newly-arrived Sims start going to work in the next tile, but gradually over time, they take over some of the local jobs as vacancies appear.  Yet some of these jobs have been taken over permanently by the Sims commuting in from the western suburbs, which is why the population doesn't rebound all the way to its previous level.

Of course, this implies that the supply of accessible jobs is a major limiting factor in this city.  How can we verify this?  Looking at the zoning, I verified what is pretty obvious:  the small commercial buildings are all in low-density zones.  In fact, all the commercial zoning is low-density.  The large commercial buildings are ploppables with jobs.  I figured that if jobs were the limiting factor, rezoning a few of these areas to high-density should produce at least some growth.  This is what happened when I rezoned:

(http://img193.imageshack.us/img193/5403/buildingsw.jpg)

You can see that the Sims didn't waste any time with medium-sized buildings.  They went straight for the skyscrapers.  Here's what it looked like when they finished:

(http://img402.imageshack.us/img402/4651/buildings2.jpg)

All the skyscrapers above the graph are new.  And sure enough, as you can see, there's an immediate increase of about 20% in jobs.  Here's what happens to the traffic pattern:

(http://img706.imageshack.us/img706/7306/traffic.jpg)

About 30,000 Sims are now getting off the expressway to go to the new jobs.  So that's why they just sped through downtown before - all the jobs were filled.

But sumwonyuno reported seeing a similar pattern with Simulator A, and no one getting off the highway when he ran Simulator Z.  How do I explain that?  Actually, I saw the same thing.  But because I ran the simulators for a much longer time (33 years for Simulator Z and 40 years for Simulator A), I saw many other things as well.  In both simulators, the highway traffic would fluctuate greatly, although in somewhat different patterns.  Although at some times, there were a constant 30,000 or so Sims traveling the whole highway in Simulator Z, at other times there were 65,000 entering the city, and 30,000 getting off at the main downtown exit.  At still other times, there were 35,000 Sims entering the city, with 30,000 getting off at the main downtown exit, leaving only 5000 on the highway after that point.  It all depended on when I looked.  But throughout all of this, the number of jobs stayed constant.  This means that the jobs were simply being traded off between the Sims coming in on the highway and the Sims living in town.  Whichever group of Sims didn't get the local jobs would go to the next tile, looking for work.  And in both simulators, there was never any residential abandonment or downgrading.  In general, what I observed simply reinforced what theory had told me:  The smaller the city, the more Simulators A and Z should behave similarly.

As for why sumwonyuno saw some of the southern jobs be filled when running Simulator A that weren't when running Simulator Z, this I can't say for sure, as I observed no difference there myself.  It could be timing, or the effect of running other cities, or almost anything.  But I was unable to reproduce any trace of this problem.

Sumwonyuno also reported that in the eastern suburbs, traffic was flowing the wrong way on the highway - away from downtown in the morning and toward downtown in the evening.  I agree with him that that makes no sense, and furthermore, it is not consistent with the morning traffic entering the city from the east that we both saw in the downtown city.  So I took a look in a couple of the suburbs that he mentioned.  I examined the traffic at the point where he gave the cities to me, and then ran both simulators on the cities from that point to see what changed.  In all cases, I found traffic flowing west toward downtown in the morning, and east back to the suburbs in the evening, just as it should.  I suspect a measurement error by sumwonyuno here.  It's easy to get the commute periods out of synch between the route query tool and the volume data display; I suspect that that's what happened here.

How does this all relate to the Destination Finder and the Nearest Destination Attractiveness property that I described in a previous post?  I believe that this investigation led me to the correct conclusions there; the only difference is that it now appears that Maxis implemented the Nearest Destination Attractiveness property properly, so that it does not interfere with perfect pathfinding.  However, I did realize something else about the Destination Finder (which must exist in some form, whatever Maxis calls it).  I have observed that in very large cities, it is usually impossible to get rid of abandonment due to commute time completely.  In Simulator Z, the only way this can be happening is if suitable jobs aren't being found for the Sims.  Yet such suitable jobs do exist in these cities.  Since it is the Destination Finder whose job it is to find them, it is the Destination Finder that must be failing here.  Furthermore, I noticed that with the introduction of Simulator Z v1.2, the number of such abandoned residences decreased by at least half.  In that version of Simulator Z, for all capacity levels I reduced the rail speeds, and increased the "Trip Starting Cost by travel type for Mass Transit" property for cars from 1 to 1.2.  So it would seem that one or both of these properties has an effect on the Destination Finder.  More research is needed here.  But for now, at least, I think that the questions raised in the Curious Case of Capitalis has been answered.
Title: Re: Traffic Simulator Z Development and Theory
Post by: RippleJet on December 06, 2009, 04:12:17 AM
I stop the game, find the local Sims going to local jobs, and in the middle of the night, I bulldoze their residences.  (Caught them Sims napping!  ;D)  Now there are no workers at those far-flung jobs.  What happens now?  Here's the answer:

(http://img189.imageshack.us/img189/4702/rebuildn.jpg)

Look at the point where the population takes a little plunge.  The job count doesn't even budge.  That's just what you would hope.  The Sims passing through town now see open jobs here, and take them instead of continuing to the next tile.  That's the only place those workers can be coming from.

You're probably right about that this is what happened... :thumbsup:

However the RCI graphs only show the capacities.
They do not show the population or number of workers.

The reason the capacities fluctuate a little over time is due to desirability.
It's the sum of all the first numbers seen in the queries...
those change every time the desirability factors are updated.

Thus, the constant commercial capacity in your graph cannot be used to verify your theory! $%Grinno$%
It doesn't tell you if sims are actually taking all jobs available,
it only tells you that the job capacity is still there to be taken.
Title: Re: Traffic Simulator Z Development and Theory
Post by: z on December 06, 2009, 04:53:24 AM
However the RCI graphs only show the capacities.
They do not show the population or number of workers.

Well, this is certainly good to know.  I remember when you explained what the numbers in the queries meant; I didn't realize it applied to the graph as well.

Fortunately, I also went around the city with the route query tool at the point that I took a picture of the graph, and I saw building by building how many jobs were actually filled.  What I saw also remained essentially constant.
Title: Re: Traffic Simulator Z Development and Theory
Post by: sumwonyuno on December 06, 2009, 06:01:03 AM
Well there goes 30 years of planning for the Kaka'ako area.  $%Grinno$%  The Capitalis City Council and Citizens Against Virtually Everything are in an uproar  :bomb:  In addition, wow the city looks nice at that resolution (and with shadows!). :P

Back to serious talk, z, I thank you for taking the time to look at my region.  I haven't been able to look at it since I mailed you the DVD.  I think you may remember back a while ago about the lack of jobs in the early stages of my region.  Yes, I understand the game has its limits, and I've done every trick I can think of to get Capitalis as close to Honolulu as possible.  Your explanations answered a lot.

It's an important point you raised, about the number of available jobs vs the number of jobs been sought in the Downtown city tile.  There obviously isn't enough available (and appropriate) jobs in that tile.  I didn't know what to make of the occasional fluctuations in the number of commuters from the east.  I really do think it's timing, as I always try to stop 10 years after on an October (I have a terrain texture issue in region view for saving during summer months).

The commuters "trading" jobs is a fascinating to think about.  Jobs in Kaka'ako (as of today) is primarily in low-rise buildings.  When you demolished the low-rise commercial buildings by the Capitol District, skyscrapers replaced them, giving tens of thousands of available jobs.  That is certainly enough jobs satisfy the 30,000+ westbound commuters.  The jobs closer to the shoreline are not taken because they're simply further away than almost all of the other potential jobs in the city tile.  You might want to try rezoning the commercial areas in Obama's neighborhood to high density to see what traffic patterns occur for Makiki residents and westbound freeway commuters.  Same thing for the Waikiki city tile.  (I'm assuming you know the places I'm talking about  ;)).

As for the eastern suburbs, I'm talking about Sector 24, 25, 26.  All commuters should be going west.  I don't believe it's me mistaking the morning/evening route query.  Assuming you haven't resaved the city tiles, try Sector 25, and don't unpause.  Query the avenue and it should say ~11000 cars westbound and ~7000 eastbound.  Those 7000 eastbound shouldn't be going to Sector 26, because there's isn't that many jobs out there.  It probably has to do with some legacy issue in my region.

Sector 22 <- 23 <- 24 <- 25 <- 26 <- 18 is the general pattern I'm aiming for, but it's not what is happening in the game.

I think some commuters from Sector 23 are going to Sector 24 because of commercial jobs in Sector 24.  From the perspective of those Sims, a Sector 24 neighbor connection is closer than jobs in Waikiki or a Sector 22 neighbor connection.  Now that I think about the order that jobs are taken, I think I know why.  The Sims in Sector 24 took the jobs within the same city tile.  The commuters from Sector 23 saw that there were no jobs available in Sector 24, but they see jobs in Sector 25.  In addition, there obviously isn't enough jobs in Sector 23, so some Sims in Sector 24 aren't willing to go there, and they see the jobs in Sector 25... and this pattern continues for Sector 25 and 26.  From Sector 26, the only place to go is Sector 18, but from Sector 18, the "next" tile would be Sector 10, and Sector 10 is undeveloped.  Sector 18 doesn't have the issue of wrong-peak-direction commuters, because the commuters from 24/25/26 don't have anywhere else to go, and "disappear".  Sector 24, 25, 26 do have the issue because they are in a chain, and these city tiles have jobs that are attractive to the commuters of other city tiles, but the jobs are already taken by Sims living in the respective city tiles.

Feel free to do testing on the one-way road modifications on my region.  I don't think I have time until after the 10th to do any SimCity-ing.  ()sad()  IMO, the game's original speeds better reflect the standard speed designations for Hawaii roadways.  15mph streets, 25mph roads and OWR, 35-45mph avenue, 55-60mph Maxis Highway.
Title: Re: Traffic Simulator Z Development and Theory
Post by: z on December 07, 2009, 03:06:52 AM
Headlines from today's edition of the Sim City News:

PH Finally Convicted in the Case of Nate's City Abandonment
All SC4 Networks Discovered to Have Infinite Capacity

I'd like to discuss the second point first, as it lays the groundwork for the first point.

In RL, the capacity of a network is generally defined as the number of vehicles that can travel on the network without causing a noticeable delay in travel times.  In practice, this means that a in a network at full capacity in RL, vehicles are generally traveling slightly below the speed limit.

In SC4, there is no speed limit as such; there is simply a network speed at which all vehicles travel.  Also, unlike RL, all vehicles in SC4 are single-passenger.

In RL, as a network carries more and more vehicles beyond its capacity, traffic slows down.  There is effectively a lower limit for network speeds, after which people will simply find other routes, or those on the network will leave it.  For highways, as an example, this speed is about 5% of the speed limit.  If no other routes are available, traffic may come to a complete halt, and network capacity temporarily drops to zero.

Things work very differently in SC4.  The Congestion vs. Speed Curve (which as Alex pointed out should be more appropriately named the Traffic Volume vs. Speed Curve) slows down traffic as traffic volume increases, simulating to some extent the congestion process that happens in RL.  But unlike RL, there is a lower limit on the speed of a congested network, and that limit is 30% of the network's nominal speed.  As the speed of a network drops, the pathfinder will automatically try to find a faster route for the Sims, and the efficiency with which it does so is governed by the value of the pathfinding heuristic (PH).  But sometimes there is no faster route.  In that case, more and more Sims may be added to the existing route.  Once the network speed drops to 30% of the nominal speed, adding more Sims doesn't slow down traffic any further, because it's already going at the slowest possible speed for that network.  So the pathfinder can keep adding Sims to that network indefinitely, and the speed will not drop any further.  (One reason this doesn't work in RL is that unlike SC4, in RL, vehicles take up physical space.)  This is how networks actually have infinite capacity in SC4.  This applies to all networks and all traffic simulators.

The infinite capacity of SC4 networks also explains why Simulator Z Classic (which has the capacity levels of the original Maxis simulator) can be used on a city of any size without causing abandonment due to commute time.  Other problems may result from extreme congestion, but the networks will carry as many Sims as they're asked to.

There is one other important piece of information here before we look at Nate's city.  Until recently, it had been generally believed (including by me) that the Commute Trip Max Time property was the maximum time that a round-trip could take, measured in minutes.  However, in this post (http://sc4devotion.com/forums/index.php?topic=9382.msg287921#msg287921), Lenny showed that this property actually sets a limit on the one-way maximum commute time.  In other words, Sims can commute twice as far as we thought they could.

This result was quite surprising to me, and you may have noticed that I have been using half of the Commute Trip Max Time value until now in this thread to describe the one-way commute time.  So I constructed a very simple experiment, described in this post (http://sc4devotion.com/forums/index.php?topic=9382.msg289195#msg289195), to test Lenny's results.  I got the same result that he did.  Furthermore, Lenny discovered that Chris (CLR1S4D) had performed experiments himself to answer this very question, and also found that this property measured the one-way commute time limit in minutes.  So we have three different sets of experiments, all independently constructed and performed, coming to the exact same conclusion.  I think that we can take this conclusion as fact from now on.

Now we're ready to look at Nate's city.  You can find a description of his experiences here (http://sc4devotion.com/forums/index.php?topic=3508.msg109642#msg109642) and here (http://sc4devotion.com/forums/index.php?topic=3508.msg111432#msg111432), but I'll include all the relevant information in this post so that looking at the originals is optional.

Nate started on a medium tile with a healthy city of two million Sims.  He switched to a newer traffic simulator to test it out, and twenty years later, his population had dropped 60%, to about 800,000.  Although this city started out with about a population almost identical to that of my Near South Side city that I've used in numerous examples, the devastation in Nate's city was far worse.  As you may recall, the population actually increased slightly in the Near South Side when the PH was raised, as the effects of downgrading (resulting in more Sims per building) were far greater than the results of abandonment.  In Nate's city, though, abandonment overwhelms everything.  The only way a traffic simulator can cause that to happen is abandonment due to commute time, and this part has never been disputed.  However, there are three ways that the traffic simulator can cause abandonment due to commute time:


We know that the first possibility is not the problem, since Nate's Sims had no trouble finding jobs with his previous traffic simulator.  It has been generally assumed until now that the second possibility accounted for the problem, and that the lower commute time limit of the new simulator, combined with the slower travel through congested areas due to lower network capacities, prevented the Sims from reaching suitable jobs within Commute Trip Max Time.  However, given the information derived in the first part of this post, it is now possible to disprove this, and show that all the abandonment was caused by the third possibility - a pathfinding heuristic that was too high for that city.  In fact, given the information derived above, surprisingly little information about the city is needed to show this.  We don't need to know the capacities of the networks involved, we don't need to know how much congestion there was, and we don't even need to look at the mass transit networks.  All we need is a basic map of the city, the speed limits of the streets and roads, and the value of Commute Trip Max Time.  From the following Traffic Volume Data view, and other pictures in the original thread, we can derive a basic map of the city roads:

(http://i91.photobucket.com/albums/k301/ditareinvented/SC4D/ScreenShot215.jpg)

The dark blue lines are roads and avenues, while the lighter lines are streets.  The speed on the streets is 40 kph, while on the roads and avenues it is 60 kph.  The Commute Trip Max Time is 17 minutes.  This differs from the previous simulator used in this city in that the Commute Trip Max Time there was 60 minutes, and network capacities were between 50% and 100% higher.  So it's easy to see why the lower Commute Trip Max Time and network capacities were suspected as the causes of abandonment.  But it's also easy to prove that they're not.

Given a speed of 60 kph for roads and avenues, a car can cover 62.5 tiles in one minute.  That means that the maximum range of a one-way commute is 17 times that, or 1062 tiles.  For the sake of argument, let's assume that all streets and roads are at maximum congestion.  (It can be shown that they weren't, but it's unnecessary to do so for this example.)  That means that a car's actual range would be 30% of 1062, or 318 tiles.  This is regardless of what the road and avenue capacities are.  This city exists on a medium-sized tile, which is 128 tiles in length.  This means that the maximum length of any trip is 255 tiles, and the vast majority of trips must be shorter than that.  So any trip that uses only roads and avenues has more than enough time to be completed, even at maximum congestion, since 318 tiles can be covered.  When you consider that some trips must use streets, you have to take into account that the Sims can cover 213 street tiles by car in 17 minutes - less than the longest possible trip.  But with perfect pathfinding, which always finds the fastest path, Sims would use streets only when necessary, and use roads or avenues for the rest of the trip.  For such mixed cases, as long as the street portion is less than half of maximum possible trip, or about 128 tiles, the trip can always be completed, even with maximum congestion.  And looking at the map above, it should be obvious that for a path between any two points on the map, only a very small fraction of that number of street tiles is ever necessary in any trip; the fastest trip always uses roads or avenues whenever doing so shortens the trip time.

So given the properties of the traffic simulator involved, the Commute Trip Max Time is not a limiting factor - trips by car can always be completed within that time to any square on the map.  And we didn't even have to consider the availability of bus or subway routes, which are present.  Therefore, we can eliminate the second of the three possible causes of abandonment for this city.  Since we already eliminated the first possible cause, that leaves us with the third possibility as the only explanation for the abandonment seen in this city.  The pathfinding heuristic used in the new simulator was .009, while perfect pathfinding uses a value of .003.  From the facts present, there can be no doubt that it was the higher value of the pathfinding heuristic, and that alone, that was the cause of all the abandonment in the city.

The point of all of this is not merely to see what happened in one city long ago.  Instead, it's to demonstrate even more clearly than any other example to date the importance of the pathfinding heuristic.  While a higher PH caused some abandonment and a fair amount of downgrading in the Near South Side, the overall population figures were not affected adversely.  In contrast, the population here declined by 60%.  For reasons such as this, I have gradually come to the conclusion that the PH is the single most important parameter in the traffic simulator.

This is not a new conclusion.  Recent research has found that the first modified traffic simulator was created by the7trumpets even before the Rush Hour pack was released, and was essentially what we now call Simulator E Standard.  This simulator is identical to the original Maxis simulator with one exception:  The PH has been lowered from the original Maxis value of .09 to the perfect pathfinding value of .003.  So I have merely rediscovered what was known more than six years ago.  I would simply like to request that simulator builders consider this and other examples when deciding which values to use for their simulator.
Title: Re: Traffic Simulator Z Development and Theory
Post by: wouanagaine on December 07, 2009, 03:27:08 AM
speaking of PH, please take a look at this  (http://theory.stanford.edu/~amitp/GameProgramming/Heuristics.html)

I've once seen a java applet where you can see the actual effect of changing PH in realtime, but I can't find it anymore
Title: Re: Traffic Simulator Z Development and Theory
Post by: z on December 07, 2009, 04:37:15 AM
speaking of PH, please take a look at this  (http://theory.stanford.edu/~amitp/GameProgramming/Heuristics.html)

Ah yes, Amit Patel's Web site!  This is where I learned basically all I know about A*.  Was there something in specific that you wanted me to look at here?

It's funny how things go full circle.  The way I first found that place was with a post that started with the following, addressed to Mott:

Seems you've been to Amit Patel webpage :)
Title: Re: Traffic Simulator Z Development and Theory
Post by: sumwonyuno on December 07, 2009, 05:16:15 AM
Quote
The infinite capacity of SC4 networks also explains why Simulator Z Classic (which has the capacity levels of the original Maxis simulator) can be used on a city of any size without causing abandonment due to commute time.

:D

Now that explains why whenever I changed the capacities for Simulator Z, there wasn't any abandonment of existing development my region.
Title: Re: Traffic Simulator Z Development and Theory
Post by: wouanagaine on December 07, 2009, 07:13:36 AM
Ah yes, Amit Patel's Web site!  This is where I learned basically all I know about A*.  Was there something in specific that you wanted me to look at here?

It's funny how things go full circle.  The way I first found that place was with a post that started with the following, addressed to Mott:

On that specific page, it explains how the PH influences the search
That was a quick reminder
Title: Re: Traffic Simulator Z Development and Theory
Post by: RippleJet on December 07, 2009, 08:23:14 AM
Regarding the naming of property 0x4a678060... ::)



The original source is Ingred.ini, made by Maxis and located in SimCity 4's Apps folder:




DarkMatter copied all the data from Ingred.ini into properties.xml,
which most people who have downloaded Reader from STEX (http://www.simtropolis.com/stex/details.cfm?id=21336) would have.
He made a slight change regarding this particular property (see the desc):

<property
    num="0x4a678060"
    type="Float32"
    name="Nearest Destination Attractiveness"
    desc="Lower scores means more side explorations but also more CPU time (Pathfinding Heuristic)">
</property>



The latest version is the one that Tropod made, tropod_properties.xml.
That is the one included in the Reader that's available on LEX (http://sc4devotion.com/csxlex/lex_filedesc.php?lotGET=656):

<property
    num="0x4a678060"
    type="Float32"
    name="Pathfinding Heuristic"
    desc="Lower value means more accurate Pathfinding, but at a cost of more CPU time/usage">
</property>
Title: Re: Traffic Simulator Z Development and Theory
Post by: daeley on December 07, 2009, 09:23:33 AM
regarding the value of PH, do we have any idea where this is used in the calculation of SC4's A* algorithm?

the reason I'm asking is that it's obviously a fraction or a multiplier to some parameter in A*'s calculations. Considering the same definitions on Amit Patel's site of f(n) = g(n) + h(n) where h(n) is related to the estimate of distance to the goal, I would think that the "nearest destination attractiveness" is a multiplier to this distance which would probably mean that h(n) is defined somewhat along the lines of
Code: [Select]
h(n) = ph * d(n,dest) where d(n,dest) is a distance measure (euclidian or manhattan, but I'd guess manhattan as this avoids calculating a root) between square n and the desti