Help With Street Layout/Traffic Problems

[goralt123]

Hey, I have been playing the city of Santa Anna for about 12 hours so far, and I have run into some minor, though inconvenient, traffic problems. Here's an overview of the city:

http://imgur.com/a/HxbvE

I really enjoy the city's street layout, and the relative abscence of obscene freeways weaving throughout the city. Ideally, I would like to keep it that way, but tunnels are definitely an option. Roundabouts are included as well, but I believe in not overusing them, I believe the two I have is enough, maybe there is room for a third. How can I fix the congestion at the key intersections between the major roads I outlined.

Also, what steps should I take in improving the layout of my public transport system. Should it be changed? Is the spacing between metro stops and the connections between lines adequate? What can I do with other forms of transports such as passenger rail and buses? Can I more efficiently utilize cargo trains?

Thank you very much in advance!

 

[Teldaril]

It is helpful to analyze where the most traffic comes from and where it wants to go ( in your case at the jam on C, E and the roundabout B/C).

You could highlight your zoning a little bit (where is industrial and what, where is commercial). Cargo train terminals in industrial areas deal with import and export but not with the delivery to your own commercial zones. If you want to reduce the delivery traffic through your city, there needs to be a cargo train terminal for the commercial areas, too.

If i interpret this right for C, a lot of traffic comes from the southern cargo train terminal and wants to deliver north.

E looks like delivery trucks that want to return to facility because this six-lane is the fastest way back.

Also at the roundabout on the G lane there are 4 very close intersections where E and G intersect. There is no huge jam but it is a potential problem.

 

[Promethian]

Consider using one way streets to funnel traffic in and out. Highways and 2 lane one ways don't create traffic lights when connected to. This means you can run a one way directly through the middle of an area and vehicles can go on and off it without stopping. Heres an example of a commercial zone I made.



See how I ran that highway straight up the middle. All incoming traffic now has a direct route with no stops to any part of the commercial area. You can do this with a non-highway one way as well but I didn't want any of my zones to face towards the entry one way. I also ran 2 lane one ways parallel on both side of the highway that exit the area so traffic that is leaving has a no stop route out as well. Commercial draws a lot of traffic. If I had just drawn in 6 lane roads with connections and the like it would all get bogged down very quickly. Especially when the game is on at that stadium. I use variations of this trick in every commercial and industrial area I make.

Here is an example of the concept used a different way:



What I did here is give a bunch of possible ways to get into the zone. See how the offramps from the highway/roundabout allow access to deeper and deeper areas. Note also the tunnel offramp that goes all the way to the back. This lets traffic split off based on where it wants to go.

Look at where traffic wants to go. Then give it ways to get there without becoming locked into a bottleneck with stoplights. Commercial and Industrial zones draw a lot of traffic. Both draw cargo delivery vehicles, both draw people going to and from work. Commercial also draws people going to shop. You have to give Commercial and Industrial traffic an easy path to reach any part of the zone from your highways or traffic will get bogged down in a bottleneck.

 

[whosthebestcop]

If you are going for a strictly grid layout it is easier to use all 2 lane streets and highways. Look at something like:
https://imgur.com/a/0UKPe

I'm usually pretty heavy handed with my highways. Each one of my large grid areas usually have a highway on all 4 sides. I strictly use interchanges to control highway traffic. Interchanges I usually make a 4 stack. Either both highways as tunnels and ramps above ground or highways above ground and all ramps underground. I find I can free the "inverted 4 stack" pretty easily and relatively fast. I usually keep it as small as the built in clover leaf. This is probably close to what I'm describing:
https://steamcommunity.com/sharedfiles/filedetails/?id=585891276

To get on the streets I use more of a NE America urban approach where there is just on and off ramps that go directly to the street. If you need an idea of an existing asset something like this could be used:
https://steamcommunity.com/sharedfiles/filedetails/?id=462537751&searchtext=dqbp

You will have high flow areas but everything flows. Because the idea is not just a grid but you are building the grid even on all sides so traffic is almost like a spiderweb. It uses the entire grid equally because almost everything has its own corridor. And without those larger streets there is no traffic lights. And mostly everything is on some kind of highway. And you can have a lot more on and off ramps going to street level then some kind of junction/interchange so the import/export/deliveries are barely on your street. They go to the closest on ramp and are on the highway system until they have to get off.

I've gotten to 250-265K population and never needed any form of cargo trains or cargo harbors. And my commercial zone was probably 40% the size of residential zone.

Mass transit I put most of my time into metros. Metros running north and south between grid areas and east and west. Bus routes only stay in their grid and I make my buses only make right hand turns. Left hand turns sometimes causes weird traffic to happen. I found if my metro system is strong almost no one uses Trams or trains unless its going to a part of the area not accessible by direct roads. If you had a different community not connected to main city for example.

Depending how big each grid section is determines how many metro lines you need. Large sections I might have 3 lines running N/S and 5 running E/W. Bus routes go on every street E/W making only right hand turns. And N/S I usually just add an extra street section with no zoning for the buses to turn around on the N/S routes.

If you want screenshots or a save let me know and I'll upload it. Sometimes the 1st grid city you is boring but after you learn how to make them ineresting because you know what works and doesn't.

 

[Teldaril]

A massive mega grid is the best option if you want to min max only population levels. I like to min max, but CS with all 81 tiles unlocked enables so much space that you never could utilize by min max grids (because the games limits will be reached soon).

Like the OP said:

[...] I really enjoy the city's street layout, and the relative abscence of obscene freeways weaving throughout the city. [...]

Currently i want to build a huge city with (for min max purposes suboptimal) big industrial zones and fewer highways. Everything should look a little bit more "natural". The only way to achieve this is by massive use of mass transit for people and massive use of cargo trains for freight. And don't forget the possibilities of policies.

Here is a part of the city. The yellow is my industrial area and the red are cargo train terminals and a cargo harbor. Currently the harbor sometimes is a little bit clogged and perhaps i have to add another terminal to compensate this, but everything else works perfectly fine without clogging. (I have no mods which alter the traffic or cim behavior/lifespan). The highway is barely used by industry.

 

[muttonnoir]

As a UK resident I am heavily influenced by my personal experience and rely heavily on roundabouts and simple on/off ramps that are common here in the UK. The sprawling over engineered solutions favoured in North America swallow up an insane amount of land and appear to both dominated and decimate communities. Complex interchanges can certainly be fun to create but kinda gild the lily for me!