• Welcome to SC4 Devotion Forum Archives.

NAM Traffic Simulator and Data View Help

Started by z, January 18, 2009, 05:24:20 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

z

This post answers questions that were mistakenly asked in the Development thread.

Quote from: Eagle on August 07, 2009, 06:01:25 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.

1. The current version is v1.1.1, which is in the current NAM.  I'm not sure which link you're referring to, but v1.1a would be very close to v1.1.1.  I would strongly recommend using the NAM.

2. Here's an extended explanation of the intersection effect that I posted over at Simtropolis:

QuoteThe 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 having red squares next to an intersection.  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.

3. I don't know.

4. I strongly recommend using RTMT wherever possible; most people should use the High version.  RTMT's capacities have been tuned for Simulator Z, although they also work fine with the other traffic simulators.

Eagle

Thanks Z.  I have only been playing the game for 3 months, so I still have much to learn.  Not quite ready to get complex with plugins, but I am interested in RTMT.  Other than a few mods to bump up capacities (private schools, etc.), the only mods I am running are the traffic simulator z & industry quadrupler.  By the way, the medium z works quite well on my city of 400k.  It has good bus coverage & a decent passenger rail system.  In fact, I had to take out some of the rail network with medium z because the Sims were so good about using it that it was making commercial zone development difficult due to low road traffic through these zones.

z

I think your commercial problems are more likely due to the industry quadrupler than to Simulator Z.  I would strongly recommend that you get rid of the industry quadrupler and install CAM, which will raise your industry capacity in a more balanced way.  I think the three most important plugins for the game are NAM, CAM, and RTMT.

Eagle

Probably will install RTMT next.  Not ready for the NAM & CAM yet.

pierreh

Quote from: z on August 08, 2009, 11:55:38 AM
I would strongly recommend that you get rid of the industry quadrupler and install CAM, which will raise your industry capacity in a more balanced way.  I think the three most important plugins for the game are NAM, CAM, and RTMT.
Aha! That is a very interesting piece of advice. I did install the industry quadrupler quite a while ago (before Simulator Z) because I got tired of having to devote large areas of my cities to industry, which is boring to zone and not too attractive. After implementing Simulator Z I did not notice any really adverse effect but I did find that further development of some cities became sluggish, especially that of commercial areas. On the other hand, installing CAM has been on my to-do list for a very long time, but I wanted to understand it well before starting to use it. The above advice is certainly a good incentive to really getting involved with CAM.

the7train

#105
Hi,
I just have a question about commute times when sims go from one city tile to the next.  Is their commute time calculated only by the time it takes to get from home to the end of the city tile?  With no regard for how long they drive in the next city?  Or is there a commute time added in for the next city? 
Also, what is the max distance or time in Simulator Z that sims are willing to travel?
Thanks!

z

Quote from: the7train on August 20, 2009, 12:53:13 PM
Hi,
I just have a question about commute times when sims go from one city tile to the next.  Is their commute time calculated only by the time it takes to get from home to the end of the city tile?  With no regard for how long they drive in the next city?  Or is there a commute time added in for the next city? 

Yes, yes, and no.

QuoteAlso, what is the max distance or time in Simulator Z that sims are willing to travel?

Simulator Z is set so that the Sims are always able to get to any of the neighboring tiles.  Since their commute time is reset once they enter a new tile, there is theoretically no limit on how far they are willing to travel.  But for various reasons which are a bit complex to go into here, it's very difficult to get them to commute more than a few tiles.  Yet that should be plenty for most people, and in real-world terms, it's not a long commute, as each tile is only 4 km long.

SC4BOY

#107
I have not done thorough testing but it certainly seems that ONEWAY roads are not as effective as they should be. I am not sure why.. if its a result of an averaging of "morning/ evening commute times, or lane counts or what I'm not sure. Have other folk observed this? I am currently using z-high due to the "bus count" giving me heavy "congestion" throughout most of my streets.

Oh I forgot to mention that the "intersection mod" that you've implemented is rather unrealistic as it gives big congestion on both the entrance and exit of intersections even when the total traffic is largely oneway. This probably is unavoidable.. I dunno ;)

z

Quote from: SC4BOY on August 20, 2009, 10:14:00 PM
I have not done thorough testing but it certainly seems that ONEWAY roads are not as effective as they should be. I am not sure why.. if its a result of an averaging of "morning/ evening commute times, or lane counts or what I'm not sure. Have other folk observed this? I am currently using z-high due to the "bus count" giving me heavy "congestion" throughout most of my streets.

In order to be compatible with RHW and NWM, all recent traffic simulators have the capacity of one-way roads set to be the same as standard roads.  This is actually how things work in the real world anyway.  The original Maxis simulator had the capacity as twice that of normal roads, but that's completely unrealistic.  One-way roads provide the biggest boost in SC4 when there is a large difference between morning and evening commute traffic on the road.

Quote
Oh I forgot to mention that the "intersection mod" that you've implemented is rather unrealistic as it gives big congestion on both the entrance and exit of intersections even when the total traffic is largely oneway. This probably is unavoidable.. I dunno ;)

Actually, this is intended, as "congestion" here is different from normal congestion, and is just used to slow down the traffic to simulate a stop light.  Even when you have maximum congestion on both sides of an intersection, the result is equivalent only to a very short stoplight.  The reason for this is that even with maximum congestion (full red), traffic never drops below 30% of the network's nominal speed.

SC4BOY

Quote from: z on August 20, 2009, 10:54:51 PM
In order to be compatible with RHW and NWM, all recent traffic simulators have the capacity of one-way roads set to be the same as standard roads.  This is actually how things work in the real world anyway.  The original Maxis simulator had the capacity as twice that of normal roads, but that's completely unrealistic.  One-way roads provide the biggest boost in SC4 when there is a large difference between morning and evening commute traffic on the road.

I rather dissagree.. in real life one ways DO significantly decrease congestion and boost capacity. why do you think crowded cities have one ways? If it didn't matter they wouldn't bother. I mean they're a PITA from a realworld perspective, but highly useful. This issue like the bus issue are simply counter reality.. (independent of whether it "gives good simulation" or not)

Quote...even with maximum congestion (full red), traffic never drops below 30% of the network's nominal speed.

That's rather re-assuring.

BTW while I'm talking at ya, I have another question.. not really simulator related, but I figure you know the game mechanics as well as anyone.. I am NOT a "My Sim" kind of guy nor do I really pretend to understand the in's and out's of them.. I do however they somehow reflect in their "opinions" the issues as the game sees them. I have a "My Sim" who says, under the heading "SIMX work commute a no-go", he lives in a "bermuda triangle" and can't get to /from work. Yet I can click the very building where he lives and there is traffic shown on the query. Do you have an idea of what is trying to be conveyed in this message?

Swamper77

Quote from: SC4BOY on August 20, 2009, 11:50:12 PM
BTW while I'm talking at ya, I have another question.. not really simulator related, but I figure you know the game mechanics as well as anyone.. I am NOT a "My Sim" kind of guy nor do I really pretend to understand the in's and out's of them.. I do however they somehow reflect in their "opinions" the issues as the game sees them. I have a "My Sim" who says, under the heading "SIMX work commute a no-go", he lives in a "bermuda triangle" and can't get to /from work. Yet I can click the very building where he lives and there is traffic shown on the query. Do you have an idea of what is trying to be conveyed in this message?

It is my understanding that this message means that it is taking too long for them to get to a suitable job for their wealth level or that there are not enough jobs for their wealth level. Keep in mind that a workplace employs very few of the upper level workers. For example, an I-HT is going to have fewer $$$ workers than $$ workers.

-Jan
You can call me Jan, if you want to.
Pagan and Proud!

z

Quote from: SC4BOY on August 20, 2009, 11:50:12 PM
I rather dissagree.. in real life one ways DO significantly decrease congestion and boost capacity. why do you think crowded cities have one ways? If it didn't matter they wouldn't bother. I mean they're a PITA from a realworld perspective, but highly useful. This issue like the bus issue are simply counter reality.. (independent of whether it "gives good simulation" or not)

Capacity is essentially determined by the number of lanes and the speed of the roadway.  Congestion is often less on one-ways in RL because of things such as timed traffic lights, which can't be simulated in SC4.  (Traffic lights of any kind can't even be properly simulated.)  However, the way congestion is calculated in SC4 tends to offset this, and it is my experience that one-way roads in SC4 definitely do suffer less from congestion.  And again, due to the requirements of RHW and NWM, I just don't have the option of giving them a higher capacity than regular roads.

Tarkus

SC4BOY, to perhaps shed a little more light on the whole One-Way Road issue . . .

Say you've got a Road heading north-south, capacity at 2400 as in Sim Z Low.  The Morning Commute shows in the Route Query as having a volume of 2400 heading north, and the Evening Commute shows as having a volume of 2400 heading south.  Since the game calculates congestion based on Morning+Evening, the overall volume would be 4800 and the game would read the road as being at 200% capacity.

Now, let's say that Road is converted into a One-Way Road, and there's a parallel One-Way a block away, forming a couplet.  The Road you converted into a One-Way Road now only takes northbound traffic--2400.  The One-Way Road is only at 100% capacity as a result, half of what it had been.  The southbound traffic has been shifted over to the other half of the couplet.

The "doubling" that Maxis did in the default traffic simulator actually results in the One-Way Road network having 4x the capacity.  And the settings they put the Avenue at result in 5x capacity over a Road.

As z mentioned, this equalization is necessary for the proper functionality of the as-of-yet unreleased Network Widening Mod (NWM).  How?  Well, most of the multi-tile networks are Road-based overrides, as they provide more flexibility than messing around with 2-tile networks.  The 6-lane Avenue (AVE-6) that is planned to eventually be included is a 3-tile-wide network.  With the default Maxis settings (1000 capacity for Road, 2000 capacity for OWR, 2500 capacity for Avenue), the AVE-6 has a theoretical capacity of 3000*, being made of 3 tiles of road.  The default 4-lane Avenue network has a capacity of 2500 per tile, meaning the overall capacity is 5000.  As such, it means the 6-lane Avenue only has 60% of the capacity of the 4-lane Avenue, which makes absolutely no sense.  And it has only 75% of the capacity of two parallel OWRs, which also makes absolutely no sense.

*It's actually lower with the Maxis Simulator due to how the Intersection and Turn Capacity Effect is set.  The AVE-6 network uses crossover paths, and as such, the game considers orthogonal AVE-6 tiles to be intersections, and applies the first value of the Intersection and Turn Capacity to their capacity.  With the Maxis setting of 0.7 (70%), this means the AVE-6 actually only has a capacity of 2100 (700 per tile), only 42% of the default Avenue. 

Hope that explains everything a little better.

-Alex

the7train

Quote from: z on August 20, 2009, 01:17:45 PM
Yes, yes, and no.

Simulator Z is set so that the Sims are always able to get to any of the neighboring tiles.  Since their commute time is reset once they enter a new tile, there is theoretically no limit on how far they are willing to travel.  But for various reasons which are a bit complex to go into here, it's very difficult to get them to commute more than a few tiles.  Yet that should be plenty for most people, and in real-world terms, it's not a long commute, as each tile is only 4 km long.

Thanks Z, that does clear it up for me slightly.  However, I think there actually is a limit if you factor in congestion because occaisionally I do see no job zots because of commute time.  If Simulator Z was set so Sims can always get to a neighboring city, then I should never see no job zots due to commute time, correct?  I guess my revised question is how does congestion affect commute times?  For example, if a road is at 200% capacity, will that double the commute time?

Thanks!

z

#114
Yes, no-job zots that claim to be due to commute time occasionally appear in Simulator Z and don't go away, leading to abandonment.  But this happens far less frequently than in any other traffic simulator, even the other Perfect Pathfinding ones.  And these zots don't happen because the Sims have run out of commute time; the maximum commute time in Simulator Z is set to (a seemingly ridiculous) five hours each way.  The reason that number was chosen was that the maximum commute time also affects the likelihood that Sims will commute to other cities, and experiments showed that this number was just right to allow significant inter-city car commuting without slowing down the game.

So with Simulator Z, there are now two reasons you can get permanent no-job zots:

1. There simply aren't enough of the right kind of jobs available for the Sims who want them; or

2. The underlying Maxis traffic simulator engine is still less than perfect about finding jobs for Sims, and it occasionally misses valid paths, even when "Perfect Pathfinding" and various other optimizations are used in the plug-in.

The first reason you can fix.  The second reason no one can fix, at least not without access to the source code.

Notice that unlike other traffic simulators, congestion is not one of these reasons.  Congestion does affect commute time, but in Simulator Z, the Sims always have as much as they need.  This is like RL, where people can choose to live as far away from their job as they want; they just allow themselves enough time to get to their jobs each day.  Congestion still plays a real role in Simulator Z, though, as it helps determine which paths the Sims will take.  Since they always like to take the fastest routes, they avoid congestion when it slows things down too much.

As for the effect of congestion on commute time, the volume of a network divided by its capacity has a direct effect on speed.  The biggest speed reduction comes when you see solid red; this always means that the speed at that point in the network is 30% of the network's nominal speed.  It is impossible to go lower than that, and believe me, people have tried.  This 30% number and the solid red color are reached in Simulator Z when a network is at 250% of capacity.

EDIT:  I should add that that 30% limit is a game bug.  We can actually put in lower numbers, but they have no effect on the speed, and they cause other bugs to manifest (e.g., the notorious Traffic Congestion Display bug).  For realistic effects, it would be good to use a lower limit of about 5%, but this just isn't possible.

EDIT 2:  Interestingly enough, there used to be a traffic simulator that featured 10x speeds and 10x commute times, and it was especially good for inter-city commuting.  It has shown that these values are equivalent in many ways to 1x speeds and 100x commute times, although keeping speeds unchanged is better for various reasons.  And that's what Simulator Z does, although its results were obtained independently by experiment.  The original Maxis simulator used a commute time of 6 minutes, while Simulator Z uses 600.  So Simulator Z essentially uses 1x speeds (approximately) and  100x commute time.

the7train

Wow great explanation!  I was trying to ease some congestion getting onto my highways thinking that was the issue.  To fix situation 1, is it best to just bulldoze the abandoned houses so that they'll grow again?  Or will the game just rebuild them?  Thanks so much!

z

It's not necessary to bulldoze the buildings; when demand gets high enough, the Sims just move back in.  On the other hand, bulldozing the buildings can sometimes speed up the whole process.  In the end, much of it depends on how much you like the current buildings.

packerfan386

#117
Hey, I was wondering what could be causing the game to suddenly revert to (sc4 vanilla) limits on commute times and whole large developments of buildings (houses) started abandoning due to commute times? The main CBD is only 2 city tiles away w/ little relative congestion between. Even completely reinstalling NAM and related files didn't help as when I clicked on ANY button on the mayor menu the game reverted to the Vanilla simulator.
I have Sim Z ultra installed and have the latest NAM, RHW, and updated NAM Essentials. Please Help!

z

Could you be more specific about what you mean by "reverting to the Vanilla simulator"?  What specifically did you observe, besides what you described?  What information are you using when you mention limits on commute times?  And what exactly is the change that happens when you click on a button on the mayor menu?

packerfan386

#119
Quote from: z on August 29, 2009, 01:40:52 AM
Could you be more specific about what you mean by "reverting to the Vanilla simulator"?  What specifically did you observe, besides what you described?  What information are you using when you mention limits on commute times?  And what exactly is the change that happens when you click on a button on the mayor menu?
1. It reverts to the SC4 default limits on commute times
2. Whole housing developments in my (well connected) suburbs have to abandoned due to "commute times"
3. The sim (z) was working fine up until I loaded one particular city and every thing has gone to dogs (stopped working) sense then.
4. After Reinstalling, the NAM simulators worked as normal until I clicked on the utilities button (to be specific) in the mayor menu, the game sputtered (froze) for a second and then it reverted the default times.

Hope This Helps/ Please Help 

regards Matthew