NAM Traffic Simulator and Data View Support Thread

[z1 566]

These are not simple questions to answer.  For more details on Simulator Z, you'll have to read much of the Traffic Simulator Z Development thread. All the NAM "simulators" are actually just a bunch of parameters fed to the built-in Maxis traffic simulator, which uses Manhattan A* pathfinding.  For more details on how this style of pathfinding works, see Amit Patel's description at Stanford.  You can find a summation of this page in this post, and some of its implications in this post, both at sc4devotion.com.  There's some pretty complex math behind all of this.  It's not a question of forcing your Sims; it's more a question of getting them to act intelligently.

[chris0101 8]

All in all a pretty impressive traffic simulator. Great work z1 and company!

[chris0101 8]

I've installed the 1.1 (not 1.1a) version with BTM. I have also gotten the enhanced traffic viewer plug in. Will try in large city soon enough. Haven't tried much with monorail, as I have built my city largely on avenues, highways, Still, the 400km/h speed should encourage at least some people to take the bullet train to work. Hopefully anyways.

Another question - should avenues have a higher capacity than roads and one way roads? If so, than why build avenues or one way roads at all? Why not just build double roads?

[z1 566]

Originally posted by: chris0101

Another question - should avenues have a higher capacity than roads and one way roads? If so, than why build avenues or one way roads at all? Why not just build double roads?

quote>

One of the basic principles of traffic engineering is that all other things being equal, the capacity of a lane of road is determined simply by the speed limit of that road.  Since in SC4, the speed limits for roads, one-way roads, and avenues is identical, each of their lanes should have the same capacity.  Traffic simulators A, B, and Z implement this principle, although it was originally put into practice for compatibility with RHW.

Following this logic, it would seem that an avenue is functionally equivalent to two one-way roads running in opposite directions right next to each other, and indeed, this is the case.  Avenues are just a more integrated road form, they're easier to build, they have those pretty medians, and they are a lot easier to build intersections for.

In RL, one-way roads are useful largely because they cut down congestion at intersections.  In SC4, this is much less of a factor, but due to the asymmetrical commute patterns between morning and evening, one-way roads will effectively give you a higher road capacity.  The exact amount depends on your traffic patterns.

[crazykid4simcity 1]

I installed the Latest NAM and chose Simulator Z. The problem is, the subway is exactly the same price as the original(154$ a segment). I use low on Z by the way. I also have the March NAM to be more specific. In the meantime, I'll probably reinstall the NAM. I don't notice any other unexpected problems. 

[z1 566]

Originally posted by: crazykid4simcity

I installed the Latest NAM and chose Simulator Z. The problem is, the subway is exactly the same price as the original(154$ a segment). I use low on Z by the way. I also have the March NAM to be more specific. In the meantime, I'll probably reinstall the NAM. I don't notice any other unexpected problems. quote>

No need to reinstall the NAM.  The subway construction cost is unchanged in Simulator Z, as it's tied into too many other things to change easily.  It's the monthly cost that was quadrupled.  (Think of it as having the subway financed by interest-only bonds.)  Unfortunately, the menu item was not changed to reflect this.  However, this was fixed in an update to Simulator Z (where the monthly subway cost was increased by an additional 50%), which can be found at the end of this post.

Modding doesn't take much time. It's the tweaking that does.quote>

No, it's the support after the release...

[crazykid4simcity 1]

Originally posted by: z1

No need to reinstall the NAM.  The subway construction cost is unchanged in Simulator Z, as it's tied into too many other things to change easily.  It's the monthly cost that was quadrupled.  (Think of it as having the subway financed by interest-only bonds.)  Unfortunately, the menu item was not changed to reflect this.  However, this was fixed in an update to Simulator Z (where the monthly subway cost was increased by an additional 50%), which can be found at the end of this post.quote>

 

 Yeah, thanks for the link. I always thought that the subway monthly costs were way too low.

Modding doesn't take much time. It's the tweaking that does.quote>

No, it's the support after the release...quote>

Heh, I didn't really think about that. The reason I don't know, is well, I haven't really modded that much other than getting the stupid colors of the zones to look right in Beta 2 of Sim Mars. I had to tweak the stupid colors like crazy.

       I also have a slight other problem though. I use quite alot of large city tiles for my cities, but when I fill it up to about 1/4 - 1/2 the city tile, the simulation always seems to stay on that same stupid day. Then, suddenly, the simulator jumps ahead one whole month and freezes again and what not. I know you changed the algorithm of the simulator's "smartness" from .009 to .003. And I know you said this shouldn't make too much of a slowdown, but I almost seem to remember that I could run large city tiles fairly ok with the simulator still running(but slowly) and stopping every now and then, but I didn't think it was this long. The longest "freeze" of time I had in a large city tile was around 1 minute or slightly less while using the "low" version of Simulator Z. It makes Simcity definitely not fun at all, but I haven't actually tested this yet. I just took from what "I" remember. I haven't played simcity for awhile, so I might reinstall the NAM and choose a different simulator to see if the speed changes any. 

Anyways, thanks for the reply. 

P.S. Great Simulator BTW

    

       Oh, I forgot to kinda tell you the quick specs of my comp to give you more insight. It is a laptop, so that might be a good reason too, but here are my specs.

  Dell Latitude E1505 Laptop

  Windows XP with 1.7GH dual core processor (This could be my problem, since Simcity can't use both processers)

  2GB RAM (I don't think anything else would be important to mention.)

[Ginufyne2004 0]

Hey Question, why does traffic in my city disappear after zooming out? It use to be that I could see traffic, well heavy traffic, but once my city develops or if the road is not running through a rural area, I can't see traffic on congestion

[z1 566]

Originally posted by: crazykid4simcity

       I also have a slight other problem though. I use quite alot of large city tiles for my cities, but when I fill it up to about 1/4 - 1/2 the city tile, the simulation always seems to stay on that same stupid day. Then, suddenly, the simulator jumps ahead one whole month and freezes again and what not. I know you changed the algorithm of the simulator's "smartness" from .009 to .003. And I know you said this shouldn't make too much of a slowdown, but I almost seem to remember that I could run large city tiles fairly ok with the simulator still running(but slowly) and stopping every now and then, but I didn't think it was this long. The longest "freeze" of time I had in a large city tile was around 1 minute or slightly less while using the "low" version of Simulator Z. It makes SimCity definitely not fun at all, but I haven't actually tested this yet. I just took from what "I" remember. I haven't played SimCity for awhile, so I might reinstall the NAM and choose a different simulator to see if the speed changes any. 

quote>

You are correct in that the slowdown is the traffic simulator running.  Normally, it only runs once every four to eight months - the game just uses the same paths in between those times.  As your city increases in population and complexity, the traffic simulator takes more time to run.  But if you look carefully, I don't think you'll see it stopping every month; it should still run at high speed for several months at a time before slowing down.

Simulator Z is tuned so that a pathfinding heuristic of .003 takes no more time than one of .09; I have tested this extensively.  And it's several times faster than Simulator A, which uses a heuristic of .009.  There are many factors that enter into the speed of the simulator, and the pathfinding heuristic is only one of them.  The slowest city I ever ran used the plain Maxis simulator, which uses a heuristic of .09, which is 30 times higher than Simulator Z's.  Having the simulator slow down for a minute every few months on a large tile is not that unusual.  Also, your CPU is a little on the slow side.

Finally, sometimes the traffic simulator will run much slower in some cities than in others that appear to be similar.  This typically happens if there are many routes that are more or less equivalent; cities with fairly homogeneous traffic layouts fall into this category.  There are a couple of things you can do to speed things up.  First of all, due to Simultor Z's increased efficiency, having lots of subways is not necessary for a well functioning city, as it is in some other simulators.  Getting rid of excess subway lines will definitely speed things up (as well as save you simoleons).  What also helps is making your traffic system more asymmetrical, putting in networks where the heavier traffic is and taking them out where it isn't.  Reducing the number of choices the traffic simulator has to make can improve its speed dramatically.

I'm curious as to which traffic simulator you were using before, and if you switch from Simulator Z to a different one, what your results are.  Please let us know what happens.

Originally posted by: Ginufyne2004

Hey Question, why does traffic in my city disappear after zooming out? It use to be that I could see traffic, well heavy traffic, but once my city develops or if the road is not running through a rural area, I can't see traffic on congestionquote>

Could you please explain in a little more detail what's happening?  This does not sound like something that is caused by the traffic simulator.  And what do you mean when you say, "I can't see traffic on congestion"?

[rudric 0]

Not everything in the game can't be realistic. Like the realism of the modding community is based on the lenght of the automata cars, while SC4 in general is far out from being realistic. Like a bus stop takes 1x1 and the automata car is only a size of small portion of that.

The getting fastest to work is not realism at all. People shop on their way to work/home, go to see a doctor etc. So forcing sims to go the straightest and fastest way is not realism.

Im also really not fond of the quadrupled subway cost.

I think there's too much in Z compared to A and B. Like why is rail pollution back in A after the latest NAM releases?

I want to test Z thats for sure and I might like it, it just seems too much of a change from A. The purpose of the game is to play it. Yes the commute time is a major part of the game, to get it low on graph but thats done by game play not with mods. Well i dont like plopped city's full of eye candy as many of the players in here fancy.

[z1 566]

Originally posted by: rudric

Not everything in the game can't be realistic.quote>

Believe me, as a developer, I am far more aware of this than most people.

The getting fastest to work is not realism at all. People shop on their way to work/home, go to see a doctor etc. So forcing sims to go the straightest and fastest way is not realism.quote>

The issue here is not whether the Sims get to work in the absolute fastest way possible, but whether they get to work at all.  The whole purpose of tuning Simulator Z is to ensure that Sims find jobs that are near them and appropriate for them.  In too many previous simulators, Sims would pass by perfectly good job vacancies, then complain that commute time was too long, and then abandon their residences.  Simulator Z was designed to fix that problem.

Interestingly, the underlying traffic simulator doesn't care how long it takes for the Sims to get home, as long as a route home exists.  So they're free to do shopping or whatever.

Im also really not fond of the quadrupled subway cost.quote>

This is still just a fraction of what subways cost in the real world.  The Second Avenue subway line in New York City has been under construction for years, with delays due to expenses.  And that's just one line.  According to a recent article I saw, subways are getting too expensive to build in modern cities, period.  Yet even with Simulator Z's increased subway costs, a well-run city can have many more subway lines than even the biggest real-world cities.

I think there's too much in Z compared to A and B. Like why is rail pollution back in A after the latest NAM releases?quote>

Rail pollution was always there.  What's back is monorail pollution, which, unlike simulators A and B, is minimal to nonexistent.  It was not intentionally put there; it is an unavoidable side effect of letting monorails get congested like every other travel type.  If the traffic simulator turned on congestion for pedestrians, they would emit pollution too.   I have not had any complaints about monorail pollution from people acutally using the simulator.

I want to test Z thats for sure and I might like it, it just seems too much of a change from A.quote>

I'll agree with you there - it's a huge change from A.  But not in the ways that you think.

The purpose of the game is to play it. Yes the commute time is a major part of the game, to get it low on graph but thats done by game play not with mods.quote>

I acutally didn't pay any real attention to commute time when designing Simulator Z.  I simply wanted the Sims to act more intelligently in terms of finding jobs.

Well i dont like plopped city's full of eye candy as many of the players in here fancy.quote>

Eye candy did not play any factor in the design and implementation of Simulator Z.

So I suggest that you give Simulator Z a try.  I think you'll find that it  behaves rather differently from what you expect.

[z1 566]

One more point for those who find their cities running slowly:  In Simulator Z, pedestrians can walk much farther than in previous simulators.  This means, as someone else has noted, that you don't need a bus stop on every corner, and in general, you can reduce the number of transit stops to a more realistic level without having an adverse effect on your city.  Reducing the number of transit stops means that the traffic simulator doesn't have to calculate as many possible branch points for travel, and it can speed up the simulator running time significantly.  It's not necessary to be miserly with your transit stops; it's just that placing them with the frequency you'd find in a real city now works very well.

[chris0101 8]

Originally posted by: z1

One more point for those who find their cities running slowly:  In Simulator Z, pedestrians can walk much farther than in previous simulators.  This means, as someone else has noted, that you don't need a bus stop on every corner, and in general, you can reduce the number of transit stops to a more realistic level without having an adverse effect on your city.  Reducing the number of transit stops means that the traffic simulator doesn't have to calculate as many possible branch points for travel, and it can speed up the simulator running time significantly.  It's not necessary to be miserly with your transit stops; it's just that placing them with the frequency you'd find in a real city now works very well.

quote>

Are sims willing to transfer between modes more so than before?

For example, say I have a BTM monorail network. The sim gets off at this network. About 5-6 tiles away is a subway stop. That subway would be much faster than walking to work. That subway leads to that Sim's work.

There are 2 options:

1. Take the BTM monorail and then transfer to the subway (FASTER)

2. Take the subway from home (suppose that there is also a subway stop close to home that leads towards work) and go to work through only the subway

If I understand correctly, this should make the Sim prefer option 1 right?

[z1 566]

Originally posted by: chris0101

Are sims willing to transfer between modes more so than before?

quote>

In general, yes.  Basically, they act like they've become smarter under Simulator Z.

For example, say I have a BTM monorail network. The sim gets off at this network. About 5-6 tiles away is a subway stop. That subway would be much faster than walking to work. That subway leads to that Sim's work.

There are 2 options:

1. Take the BTM monorail and then transfer to the subway (FASTER)

2. Take the subway from home (suppose that there is also a subway stop close to home that leads towards work) and go to work through only the subway

If I understand correctly, this should make the Sim prefer option 1 right?quote>

Probably.  However, the underlying Maxis traffic simulator is imperfect; "perfect pathfinding" is a bit of a misnomer, as it refers to finding the shortest distance, not the fastest path.  So Simulator Z makes the most of what the Maxis simulator can do.  In the vast majority of cases, since the Maxis simulator does heavily weigh the amount of time it takes for the Sims to complete a trip, this means that the Sims will find the fastest path, but not always.

[z1 566]

This thread has been renamed "NAM Traffic Simulator Z and Data View Help" to indicate that it now includes support for the new data views introduced in the June, 2009 version of the NAM, along with the previously existing Traffic Volume View. Any questions on these data views, as well as on Simulator Z, should be posted to this thread. The first post of this thread of this thread has been updated to include complete information on the current version of Simulator Z, as well as on the new data views. Release notes for the current version of Simulator Z have also been included, so that current users of this traffic simulator can see what has changed since the last release. Documentation for the new Subway View, Subway Building View, and Zones View has now been included in the section "Traffic Volume View and Other New Data Views." The first two of these, along with the Traffic Volume View, are now automatically included for all traffic simulators, while the Zones data view is optional (though highly recommended), and must be specifically selected during the NAM installation process.

[chris0101 8]

Are the BTM versions of simulator Z v1.1a still compatible with the June NAM or has a later version been released? Thanks in advance.

[z1 566]

Yes, that version is the latest released for the BTM, and it is fully compatible with the June NAM. The only difference between the BTM version fo Simulator Z and the one in the NAM (aside from the BTM support) is that the NAM version supports pedestrians walking along the side of RHW-2's. Eventually this will make it into the BTM version, but if people really want that sooner, I'll schedule that feature.

[chris0101 8]

Tried using Z Ultra v1.1a BTM version with the NAM June 2009 version. No bugs to report. Seems to be working fine.

[chris0101 8]

Scratch that - one possible error where the BTMs cross over the streets:

Traffic Direction (all traffic is moving towards an neighbouring city):

Enhanced Traffic Congestion View (NAM June 2009)

Enhanced Traffic Volume View (NAM June 2009):

I am using Simulation Z Ultra BTM v1.1a. Simulation Z Ultra should not be jamming at this capacity; the cap is 12,000.

[chris0101 8]

On an unrelated note, speaking of neighbouring cities travel, z1, what is this ESURE that I hear talk about and how does it prevent the eternal commuter bug?

sc4devotion.com/forums/index.php

[chris0101 8]

Better link:

sc4devotion.com/forums/index.php

[z1 566]

Originally posted by: chris0101

Scratch that - one possible error where the BTMs cross over the streets:quote>

Although the Ultra road capacity is 12,000, that is per day, and the Traffic Volume View works by commute period.  So for the Traffic Volume View, full capacity for a commute period is considered to be half of the daily capacity, or 6000.  This is reflected in the Traffic Volume View's legend.  Road traffic in Simulator Z includes both car and bus traffic, which according to the figures in your picture, is 8260.  So the Traffic Volume View is correct in displaying a color well into the yellow.  It doesn't matter if there's no traffic on this road in the other commute period; the Traffic Volume View only knows about one commute period at a time.

[chris0101 8]

So why does the congestion map display the tiles where the monorail overpasses the road as red and the rest as just blue? The monorail displays as light blue coloured (about 15% used in capacity). Or is just that because the game has limitations that prevent it from distinguishing between the 2 types of traffic? (This could be problematic I suppose with the tram on road/avenue/street, as there are 3 modes of transportation intersecting.)

Congestion shouldn't be severe at 130% traffic should it?

UPDATE: Never mind, apparently, the congestion graph does seem to be flawed. I suppose that I'll just ignore the messages for now. The only real useful graph is the volume graph as it tells you the real traffic volume and general direction.

Also, has there been a 1.1.1 BTM version of Simulation Z released?

Thanks in advance.

[z1 566]

Originally posted by: chris0101

So why does the congestion map display the tiles where the monorail overpasses the road as red and the rest as just blue? The monorail displays as light blue coloured (about 15% used in capacity).quote>

I assume you mean "green" and not "blue."

Congestion shouldn't be severe at 130% traffic should it?quote>

No.

UPDATE: Never mind, apparently, the congestion graph does seem to be flawed.quote>

Actually, although it's sometimes buggy, in this case it's correct.

I suppose that I'll just ignore the messages for now. The only real useful graph is the volume graph as it tells you the real traffic volume and general direction.quote>

The congestion view is actually giving you valuable information here that is not obvious from the traffic volume view.  The key here is how the game handles intersections.  (I'm talking about just the road intersections here; the monorail doesn't enter into this.)  The Prima guide inaccurately states that a vehicle's speed is reduced by a certain amount 0, 1, and 2 squares from an intersection.  In reality, what's reduced is the network capacity.  This means that where there is plenty of excess capacity, the Sims don't even slow down at intersections, much less stop for red lights.  (Or as a Boston cab driver once famously told me, "You seen one red light, you seen 'em all" as he zipped through one.)  Simulator Z is the only traffic simulator that actually reduces capacities around intersections enough to cause heavy traffic to slow down enough to simulate at least a short stop light.  And this is the best that can be done because, as was discovered painfully by a number of us, it is not possible to make congestion reduce traffic speed below 30% of the network's nominal speed.  And in fact, in all the traffic simulators, anywhere you see solid red on the congestion map, traffic is moving at 30% of its nominal speed.  This means, of course, that the Sims still don't stop at traffic lights.  But at least now they slow down.

As for what the intersection effect is in Simulator Z, like Simulators A and B, it has to be zero in the intersection itself in order not to break RHW and NWM.  But instead of the slight reductions in capacities in other simulators, which generally have little or no effect on vehicle speed, in Simulator Z, network capacity is reduced by 80% in the squares directly adjoining an intersection, and by 60% in the square that's two squares away from the intersection.  This explains your red squares next to the avenue.  And this makes sense; if you have a heavily traveled road, you're going to want to have a stoplight at the intersection.  I seem to remember that I once figured that having two red squares on each side of an intersection is equivalent to having a stoplight with a 30 second cycle, with no other congestion effects due to surrounding traffic.

Also, has there been a 1.1.1 BTM version of Simulation Z released?quote>

No, as the current 1.1a BTM release is essentially identical to the 1.1.1 general release.  The only difference is that the 1.1.1 release allow Sims to walk on the side of RHW-2 roads.  Eventually this will make it into the BTM version as well, but right now, it doesn't seem too urgent.

[chris0101 8]

Originally posted by: z1

No, as the current 1.1a BTM release is essentially identical to the 1.1.1 general release.  The only difference is that the 1.1.1 release allow Sims to walk on the side of RHW-2 roads.  Eventually this will make it into the BTM version as well, but right now, it doesn't seem too urgent.

quote>

I'll just use the 1.1.1 version and push up the monorail speed to 400. After looking through Ilives, there are no major differences; just the walking that you mentioned.

I tried experimenting with 500 and 600 km/h as well with the version 1.1.1. Beyond about 600 km/h, I'd say that most Sims have made up their mind; monorail is the best way to go. At 700km/h and even 800 km/h, there were no major increases in BTM (or monorail) traffic. Seems reasonable enough to me. (Speaking of which, the idea of a train going at 800 km/h may seem pretty far off for now, but when you consider the current maglev testing speeds, it may very well be possible in a few decades).

In theory at an intersection, traffic would be traffic going on one road + traffic going on the other side + perhaps a slight delay in the signal changes (maybe slow it down by 10%?). If it is jammed on one road, it will be even more jammed on an intersection. Your simulation Z is pretty realistic in this respect. Still, the slowdown appears to be temporary as Sims start to pick up speed once they clear the intersection again. Bottlenecks can also occur near highway interchanges. Another side effect seems to be a pretty high amount of car accidents around the intersections; again realistic like in real life.

[rebs 1]

I haven't heard anyone mention how their monorail intersections no longer form nice circles with this mod.  Have I done something wrong?

[z1 566]

This change actually has nothing to do with the traffic simulators; it was made to all the rail networks by the NAM Team. The idea is that all turns at intersections are still possible, but those tight circles were unrealistic, and often caused the automata to go around in circles.

[darn42 1,268]

that's weird, every one of my sims is walking now, none have cars, even the high wealth. It makes it real hard to play. but my cities that already have cars in them still do

[rebs 1]

I have watched my monorail paths and found that after sections of the rail were removed by the plugin, the monorails are no longer able to go straight ...also, there are remnants of the circular sections of track where they once formed the aesthetically pleasing loops.

I am pretty sure there are other issues as well, as I cannot discern any change in capacities or speed. Actually, my cities become dark with abandonment, likely because the monorail system is forced to take circuitous routes to destinations.

The only way I know the NAM was installed at all is by the presence of a few different road pieces and the aforementioned monorail problem. Clearly this is not working for me the way it's supposedly working for others.

Any help would be greatly appreciated. Thanks

PS. As far as tight circles go, I am still able to build them out of rail....just not monorail

[doorknob60 11]

Too many people are using the subway recently Any ideas?. See here: https://www.sc4devotion.com/forums/index.php?topic=6812.msg258240#msg258240