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NAM Traffic Simulator Development and Theory

Started by z, August 02, 2008, 05:07:50 PM

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sumwonyuno

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  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.


The City & County of Honolulu, a Mayor Diary based on Honolulu, Hawai'i.

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z

Quote from: sumwonyuno on August 21, 2009, 04:27:42 PM
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.

QuoteThere 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.

QuoteThere 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.

sumwonyuno

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.


The City & County of Honolulu, a Mayor Diary based on Honolulu, Hawai'i.

mark's memory address - I've created a blog!

z

Quote from: sumwonyuno on August 22, 2009, 12:59:19 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?

sumwonyuno

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.


The City & County of Honolulu, a Mayor Diary based on Honolulu, Hawai'i.

mark's memory address - I've created a blog!

z

#185
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 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:


  • A Bus Usage Multiplier, which would allow the player to control the relative usage of buses in the traffic simulator.  The initial setting would be 1, which would reflect the current usage level, and this value would be calibrated in tenths, with a range of 0.1 to 9.9.  (Zero doesn't actually work as expected if valid paths are available.)
  • A Highway Bus Lanes checkbox, which would simulate the existence of bus lanes on highways, although of course the automata would not reflect this.  But this last fact would not necessarily be obvious; you could also call it a carpool lane, to explain the presence of cars, and some buses would be traveling in other lanes anyway.  This could be combined with the Bus Usage Multiplier to produce a multiplicative effect.
  • Allowing the players to tweak the monthly cost of all the networks.  Although the purchase cost for network tiles is accessible, it's often tied up in exemplars with properties that are changed by other mods, so it's risky to modify those exemplars.  But the monthly costs exist completely within the traffic simulator.  And realistically, cities don't have bundles of cash sitting around for big construction projects anyway.  So the monthly costs can be considered payments on interest-only bonds that the cities issue to build the networks.  These costs can be made more or less expensive to suit the player's preference, and each network can be tweaked individually.
  • Similarly, the players could adjust the fares for each travel type any way they wanted.  As an example, you could make your ferries traveling riverboat casinos, and charge the Sims ยง100 just to board.  That would solve your financial problems fast.  This wouldn't deter the Sims from taking ferries; they just don't know the value of money.
  • The intersection effect could be changed, effectively making more or fewer stoplights and stop signs in cities, making traffic flow smoother, or making a complete mess of it.
  • The commute time graph scaling could be changed by the player.  This is useful because the proper scaling depends on the type of region that the player builds; specifically, it is dependent on the number of inter-city commuters.
  • Finally, the amount of air pollution emitted by vehicles could be tweaked by any amount in either direction.

Comments are welcome, as always.

RickD

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.
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sumwonyuno

[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?


The City & County of Honolulu, a Mayor Diary based on Honolulu, Hawai'i.

mark's memory address - I've created a blog!

z

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.

z

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?

emgmod

I always wanted to modify fares. I like the idea.

sumwonyuno

#191
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.


The City & County of Honolulu, a Mayor Diary based on Honolulu, Hawai'i.

mark's memory address - I've created a blog!

z

Quote from: sumwonyuno on August 27, 2009, 01:57:11 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.

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.

k808j

@z

Would sim z medium cause the sims not to use the buses or bus use not show in traffic data view?

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z

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 thread?

HappyDays

#195
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!

z

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.

redraider147

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.

ldog

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)


z

@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.

QuoteRead 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.