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NAM Traffic Simulator Development and Theory

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

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z

Currently, the following minor updates are planned for the next release of Simulator Z, which will be V1.1:


  • Fix monorails to contribute to and be affected by traffic congestion, just like all other vehicles.
  • Adjust the speed of the el rail trains slightly downward, to be equivalent to the subway speed.
  • Fix the display of the monthly subway cost in the menu.

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:


  • Further optimization of the pathfinder to make Sims' travel patterns even more realistic.
  • A further increase in monthly subway tile cost, to more accurately simulate the real-world cost of subways.  (Almost like a fare increase... ::))

Currently, Simulator Z has a monthly subway tile cost of ยง1.20, 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.

b22rian

Im ok with doubling the sub way cost...
But no higher than that i think..

Thanks, brian


b22rian

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

mike3775

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.

z

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.

b22rian

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


mike3775

stupid question time, but how would I place this update into my NAM folder when I used the DAT packer?

z

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.

mike3775

Ahh ok.  Thanks, will redo the Dat packing right away then

Thanks

z

#149
Quote from: b22rian on April 22, 2009, 09:13:42 AM
Ok Z ,here are the results of my 6 year test using the bullet trains at 400 k/h as you suggested....

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.

b22rian

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

z

Quote from: b22rian on April 23, 2009, 04:06:36 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.

z

#152
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.

z

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.

z

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!

z

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.

shlarin

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.

z

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.

Eagle

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.

z

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 thread.