Insane Congestion Problem

[Fatherted 129]

My city's population is 145,000, or something similar. People travel from one city, through another, to get to mine. Mine do the same. I have been reduced to having two completely red lines running into that central city, each at around 60,000. One connects to it's main subway system, and one runs straight through with only 1 stop and no intersections. Soon I am going to have to run double subway lines around the city, and double stations (from 15000 to 30000 cap), and I have had to introduce a dual rail line into a different city, with 65000 using 1 and 12000 using the other. The rail is also part of the subway with a connection lot, as is my small amount of tram, which is also overused (5000) and my other rail link is sitting at 6000. My actual connection to the city causing some of the problem is at 26000 usage (monorail) with the station sitting painfully at 260%. HELP!

[grstudios 188]

It seems quite odd that such congestion can be genereated from such small population....

1. Are you using any mods? If so, it may aeffct your traffic patterns.

2. How are the cities aligned and connected to each other? You'll have to be specific and write those connection, because it might be the infamous commuter loop which wreak havoc in your city...

[Darkwings 5]

I'm having a similar situation with 1 medium sized city @25k pop (just started to generate money, power and collect garbage) and 1 big sized city @50k pop (covering 1/8th of the map).

Also, I'm using NAM with medium settings.

I'm handling the traffic inside the cities efficiently with monorail and avenues, and I have a stretch of highway connecting the 2 cities.

Even with that 'low' population, the highway is over 300% usage, if I were to grow some more the big city it would soon explode.

That's to say, it's quite possible to have congestion if you are actually managing to get the main systems to full usage.

You just have a bottleneck on the huge main system right? So it means it's working as intended since it's gathering all the traffic.

Split the incoming traffic on 2 different main lines (parallel lines, alternative ones or whatever you can fix in your city).

Also, avoid making new intersections. That the best way to ruin the flow, and you will have the same result on the main side of the system.

Anyway, 260% is not enough to change a whole _working_ system like that. Wait to see if it reaches 350%+ and in meanwhile try to make some room for a twin system

[Mootilda 76]

It really sounds like you might be running into the "eternal commuter loop". Search this site to understand the problem and how to design your cities to avoid it.

[Fatherted 129]

I checked...I haven't. It turns out the tram is not 5000, but 55,005! Here is the alignment:

Large City-Middle City

Job city-Congested City

I have used rail-to-subway, and GLR-to-subway, and high capacity stations (10-15 thousand subway, 5-6 thousand rail, 20000 big subway, default ferries are taking over 70000 per day (?) and 1500 GLR).

[z1 566]

There is nothing necessarily wrong with your city. I have seen cities about your size with even greater congestion, and it's just due to the way the cities are laid out. When you use custom content, you can get a lot more traffic than the Maxis stations were designed for. That's why the NAM traffic simulator has network capacities up to twenty times as high as the Maxis simulator. That's also why RTMT Tram-in Road stations have more than 50,000 capacity, and Tram-in-Avenue stations have much more than that.

with 65000 using 1...

That number wouldn't actually be 65,535, would it? That's the maximum that the traffic volume counters can hold (2¹⁶ - 1), and it means that the actual volume is undoubtedly higher. You can get an idea of how much it is from the Traffic Congestion Data View, which isn't limited by these numbers. Just remember that it includes both morning and evening commutes.

In my cities, I often have a dozen or two subway lines connecting cities where the lines are pretty much maxed out; this is using the Ultra version of the NAM traffic simulator. And there are definitely no eternal commuter loops there.

with the station sitting painfully at 260%.

It should be considerably less painful if you know that (contrary to what Maxis says) mass transit stations suffer absolutely no performance degradation whatsoever until they're at least 400% of capacity.

It seems quite odd that such congestion can be genereated from such small population....

It all depends on the layout of the city. I've seen a standalone city about the same size where one Tram-in-Road station had a usage figure approximately equal to the city's population. Since the city's workforce is only about half the population, how could this be? Simple: Station usage figures include both morning and evening commute; so everybody got counted twice. And that station really was a bottleneck between all the residents and all the jobs, so all the Sims had to use it.

Even with that 'low' population, the highway is over 300% usage, if I were to grow some more the big city it would soon explode.

I've never seen a highway that congested. Are you looking at the Traffic Congestion or Traffic Volume Data View? If you're looking at the latter, you may see these figures, but you'll also see a little disclaimer that all figures are based on road capacity - even the highways. There's no way around this in the Volume data view.

Also, avoid making new intersections. That the best way to ruin the flow, and you will have the same result on the main side of the system.

Again, despite what Maxis says, intersections have virtually no effect on traffic flow. Sims never stop at them, and usually they don't even slow down.

  Edited June 26, 2012 by z1  

[Darkwings 5]

I didn't mean intersections slow down the traffic, they just 'ruin' the flow if the flow is already good.

Creating a new intersection will create new paths, unavailable before, so of course you'll have to handle a different situation after that.

If all the paths eventually lead to the same bottlenecked place, adding more intersections won't solve the bottleneck, just that.

Also, since I'm having trouble finding something decent: is there a monorail station with increased capacity that isn't a deus ex machina all-in-one wonder?

I don't want sub+bus+mono+whatever, I just want a monorail station that could match the NAM capacity :|

About the highway, that value is under volume data view. I wasn't very clear in my previous post, what I actually meant is that I'm reaching the max capacity : I have 14701 cars while medium NAM can hold 15k. The 300% is just the volume data view color-code.

  Edited June 26, 2012 by Darkwings  

[Darkwings 5]

Never mind, I finally found ONE mono station with a decent 8k capacity (I would consider anything else cheating )

[A Nonny Moose 8,261]

Never mind, I finally found ONE mono station with a decent 8k capacity (I would consider anything else cheating )

In desperate situations, I use the BSC Monorail station that is dual tracked and handles 30,000 Sims. This is not a cheat, just a big station. It is quite large and expensive.

[Darkwings 5]

Thanks for the info but while money isn't really a problem, size is. A 3x1 or 4x1 is all I can fit into an R zone at the moment, and I need to handle up to 12k commuters per station.

On the other hand, I got this problem now:

Sorry for the high-jacking, I'll just keep my stuff in the other thread.

[A Nonny Moose 8,261]

Well, so demolish enough stuff to get your stations in. Don't be shy, any city administration would simply expropriate and do it.

Oh, and terminals are better than stations on a through track. Terminals have no through tracks and are on spurs.

  Edited June 27, 2012 by A Nonny Moose  

[jorgedasilva 0]

I have a similar issue. most of my cities have 100,000-1,300,000 people and its grid lock so i upgraded my roads to 4 lane roads (2 lanes per side) to 6 lane roads/TLA 7.it didn't work as well as I hoped it would congestion is building up as my population in the region is rising to 30 million people.

[A Nonny Moose 8,261]

Best solution for congested roads is subways.  Also, how about alternate routes.  Buses don't solve anything because they are not multiple passenger devices, just different kinds of cars.

 

If your subways become overloaded, dual them.  Also try surface rail and monorail, even if you have to do some urban renewal projects to get them in.  You are the boss, and buildings shouldn't be allowed to get in the way.