Do our transit systems reduce traffic?

[Norfolk_Chris]

I have not noticed any reduction in traffic congestion in my cities, even when I have 90%+ coverage, and 90%+ overall CIM satisfaction. Surely a good transit system should produce a reduction in traffic congestion? This, I believe is a basic fault in the game that should be fixed.
Do your cities behave in the same way, or is it that I'm doing something wrong?
(A comment from CO would be most welcome.)

 

[Arko]

I'd like to know this aswell.

 

[co_martsu]

I have not noticed any reduction in traffic congestion in my cities, even when I have 90%+ coverage, and 90%+ overall CIM satisfaction. Surely a good transit system should produce a reduction in traffic congestion? This, I believe is a basic fault in the game that should be fixed.
Do your cities behave in the same way, or is it that I'm doing something wrong?
(A comment from CO would be most welcome.)

Good transit system surely does reduce the traffic congestion! People who tend to walk are easier to attract than the people who own cars. So usually in the beginning you don't see so much effect on the traffic congestion. However if the service is good enough, people will switch the private cars to public transport also

 

[Arko]

Good transit system surely does reduce the traffic congestion! People who tend to walk are easier to attract than the people who own cars. So usually in the beginning you don't see so much effect on the traffic congestion. However if the service is good enough, people will switch the private cars to public transport also

Thanks for the answer. IIRC Traffic giant had a specific indicator for that "traffic reduction" or such, could we have something similar in CiM2 somewhere in the stats ? it could make a good game objective or achievement.

 

[co_martsu]

Thanks for the answer. IIRC Traffic giant had a specific indicator for that "traffic reduction" or such, could we have something similar in CiM2 somewhere in the stats ? it could make a good game objective or achievement.

Thanks for the idea, let's see what we can do

 

[Arko]

great to hear^^

 

[unmerged(266137)]

This may be counterintuitive, but: there is no guarantee that a real-life transit system will reduce traffic congestion. This is due to the induced travel effect.

Congestion is an sign of equilibrium between number of people who want to travel and the amount of mobility available to them. If you provide more mobility by improving public transportation, or by adding more lanes to roads, then the equilibrium will settle at a new level with more people travelling. There will still be congestion and delay, but more people will be able to get around.

Read more about it: the Downs-Thomson paradox, the Lewis-Mogridge position, and articles about induced demand.

Note that this effect only applies where there are sufficient numbers of people to provide a source of nearly limitless demand on transportation: for example, to a city center. But the idea is really simple. If so many people switch from roads to rail (for example), then the roads will become improved to the point where they attract people back onto them, until it gets congested again. Equilibrium.

So in the game, if you do some kind of traffic reduction due to existence of public transport, then it is an artificial factor. Ideally, you should simply model desire to get from source to destination by the best mode, and let it play out. You should also consider destination parking availability as a significant factor in choice of car mode (this isn't explicitly modeled in the game AFAIK). If the player is actually able to exhaustively satisfy the population's demand for transportation service along certain segments, then you'll see traffic congestion thin out there. But either way, providing enhanced transportation links will allow larger and larger numbers of people to travel regardless of the level of congestion. And that's what (grade-separated) transit provides.

 

[Svip]

Thanks for the idea, let's see what we can do

Isn't the main problem that buses are also traffic themselves, so they also introduce more traffic. So a non-carefully planned transit system will induce more congestion.

 

[ThrilledCim]

I have not noticed any reduction in traffic congestion in my cities, even when I have 90%+ coverage, and 90%+ overall CIM satisfaction. Surely a good transit system should produce a reduction in traffic congestion? This, I believe is a basic fault in the game that should be fixed.
Do your cities behave in the same way, or is it that I'm doing something wrong?
(A comment from CO would be most welcome.)

They DO reduce traffic but you won't notice it until you have 100% coverage, i.e. no red. at least all yellow on the map. As long as you have some uncovered areas, cims will continue to drive there and somehow driving is contagious. Once they see their neighours drive, they all have to drive and that's when you get really congested roads and especially expressways. You have to build lines that EXACTLY replicate the area of congestions and make sure cims can get to those stops. For example, if you see an expressway completely congested with cars back to back and not moving, you have to build a transit line EXACTLY right over or under the expressway covering the ENTIRE expressway. And you have to make sure cims can get to the stops on that line that might be right on the expressway. Don't worry. Cims are all very savvy and brave pedesterians and can walk through any highway traffic to get to those stops no matter how fast the cars zip by them. Sometimes the cars are so scared of them they stop in the middle of the highway to let them pass.

If you did build transit lines that allow the cims to go to where they wanted to go without cars, you will notice their method of transportation change from "Private car" to "Public Transport" if you continue to monitor them. You will feel really good when that happens right in front of your eyes. Have fun!