[BUG.. or not?] Cities Skylines Traffic.. serious issues!!

[Agent cooper]

Although loving this game, traffic handling or ai is disappointing. I am very surprised that so many individuals seems happy that the current method that cars line up in one lane on a two or three lane road is okay. I have read the argument that its a game and we should know the rules on how to play. I will counter that since its a city simulation the rules are already know since they are based somewhat in reality and real life expectation. The planning of roads to fully distribute cars is apparently a work around to get the expected effect when one lays down a multi lane road. If a person has to constantly think about turning traffic instead of thru-put of traffic, then what is the use of having multiple lanes of cars congregate in one lane to turn even if they are turning on a two lane on direction road from a multi lane bi-directional road. I for one just don't get the advocacy argument of this being fine.

If your 2-lane one way road they are turning on has an exit to the left they will use both lanes! (to be precise, the cars that want to go left will use the left lane) But if all your cars can only turn right why should the use the left lane? It won't be any faster because all cars have the same speed. They will have to get back into the right lane to be able to turn right and to achieve that they will either have to stop an wait for a gap or the right lane has to stop and let them in. Both will make your traffic even worse.

 

[PMV]

Ok, it's hard on some of these pictures to see what actually goes on.

Sorry, have made black lines to show the flow. That is exactly whats going on. Bad if that doesn't help that much

On the first picture: The cars coming from the bottom road want to go to the left lane because they want to turn left at the next junction (and then probably left again right after that)

Yes. Thats right. But there are 6 lanes for turning left. Not one. And the next still haas 3 lanes for going left. But they even some going to the right lane then. So All 6 lanes could be used with that logic.

You shouldn't let them enter this road from the right side. This would cause traffic problems even in the real world. Unless you have traffic lights of course.

Thats not a problem here as they just get backed up because of the next crossing where they don't use enough lanes.

In the second picture: Well they have to switch lanes somewhere. Doesn't really matter where. It seems that you use way too many lanes at the road that comes in, though. At this point 3 lanes would be enough.

The second picture is only to show the cars on the outer left have and do turn right after the crossing. So it would be no problem for them to use the 6 lanes before. Its clear that they have to somewhere. But in this case, it is to late.

Third picture: the left road that goes straight on would only need 3 lanes if your off going road is a 3-lane road that has roads going off in three different directions (left, straight, right). Otherwise the middle lane is completely useless. On the road that goes to the left: Are you sure this car wasn't coming from the little one-lane ramp? Because then it couldn't change earlier.

I'm sure. 50% Of the cars are going to the left lane, 50% stay on the right lane. All cars coming from that road. This showes again, that the cars are choosing the lane to late/ early. AND as the one staying on the right lane get stuck on the next on-ramp, they choose the lane to early as the middle lane is free and this highway leads to another highway with 3-lanes. But ther

You have to design your on- and off-going in a way that the cars have to switch lanes as less as possible. That means, if you have a lot of cars entering from the right bunt want to gol left you should build it in a way that they enter from the left.

I know, but thanks. The road network works pretty well, except this big crossing because the cars don't use all possible lanes, even so they are all leading to the same long highway

MFG PMV

 

[Agent cooper]

@PMV:
You always have to keep in mind that all cars have the same speed! So the cims always take the route where they have to change lanes as less as possible. Because they can't overtake other cars. Eventually they will have to get back to the lane they need to be. And since they are not faster than any other car they either have to wait until they find a gap or the other lane has to stop to let them in.
You have to give them a road system where it's possible for them to don't change the lane at all. And that is (almost) possible.

 

[s0cks]

IF it's not possible to mimmick more human like behaviour of lanes then we need more road tools. I'm pretty sure CO have told us such tools are inbound right?

 

[PMV]

@Agent cooper
You can workaround the bad behaviour or point the problems out to the devs to have a chance of getting a better version.
I can build a highway and roadnetwork, where no lane-changes are needed. Like using only one-way roads and so on. But i don't want to.
Some times i want to use big 6-lane-crossings with traffic lights, so cars have to use more lanes to get them useful. They have to change again after that crossing, of course. But as a traffic light will take time to turn again, there is enough time to change lanes without causing big jams. Especially, if later the cars on the side have already used the off-ramp :laugh:

MFG PMV

 

[AmpsterMan]

I don't quite understand the issue with traffic people are having; if three is one right turn lane and everyone needs to turn their, how else are they going to do so? This would be the same case in real life! In fact, I've seen out inn my home town. I'm thinking people are also adding to adding too many intersections. Unfortunately, all road crossings right now cause intersections to appear so every stop is a traffic light. If you mamake an intersection every 8 squares or so (two houses back to back) that's roughly 8 car lengths. Imagine living in a city where the distance from one intersection the other is 8 car lengths; it would be a nightmare!

Unfortunately, the only way to work around this atm is to make what i call boulevards (two way streets both ways) because they don't cause intersections when only crossed from one side. If could get streets to only make stop signs, this ould be great!

 

[Aytumious]

Vehicles choose the right lane for their purpose fairly early. In the first message all the vehicles are going the same way from the next intersection, so they queue on the lane that allows them to go that way. During development we tried having cars use all lanes and just switch to the one they really want very late, but that created a HUGE mess, the turning cars blocked two lanes and didn't let cars behind them proceed. The one lane queue looks funny, but actually works quite well. Even if the cars would be on all lanes, they could not all fit to the street they are going, so the traffic jam still tells you of something being wrong with your road system

Hello Co_Karoliina,

I'm wondering if you have considered adding a basic weighting system to the pathing algorithm so that traffic congestion is factored into what route an agent will take. I know that currently the speed of roads does factor into pathing, so perhaps adding a similar system based on congestion would help to make the traffic a bit more fluid. It could be set to only trigger when a rather high threshold of congestion is met.

I'm not a programmer so perhaps that would be too resource intensive even at a fairly basic level.

 

[playn2]

If you're having that kind of pileup on one lane, then the solution is rarely "move the cars into the other lanes for nice even congestion." I mean even saying that sentence sounds stupid.

Nobody loves this design decision or thinks it's perfect. A lot of people though are saying that if this design choice is a problem, it's usually because it's highlighting a bigger issue for your town's traffic flow.

It's really easy to design a town that doesn't have the one lane stacking bug as a prominent feature. If you haven't managed it, the solution is not to whine on the forums, it's to work harder at systems analysis and fix whatever's broken in your own traffic system.

I beg to differ with your statement as you are hypothesizing that thru-put would not alleviate the problem. That is something you cannot even test in this simulation. One of the very reasons there are more than one lane on a road is to handle more traffic/thru-put through an intersection. The current build of this simulation's traffic AI does not afford such an expected action (instead gives unexpected results). Therefore, I am a bit amazed that you in all your "wisdom" have reached the conclusion, that the primary fault is with the design, absent the contributing factor of the traffic AI (the topic of my whining).

 

[playn2]

If your 2-lane one way road they are turning on has an exit to the left they will use both lanes! (to be precise, the cars that want to go left will use the left lane) But if all your cars can only turn right why should the use the left lane? It won't be any faster because all cars have the same speed. They will have to get back into the right lane to be able to turn right and to achieve that they will either have to stop an wait for a gap or the right lane has to stop and let them in. Both will make your traffic even worse.

Because if that left have a two lane exit they should...even if it was a one lane exit they should still use both lines to turn. It would truly indicate the very origin of the problem instead of everyone guessing and designing around unexpected behavior.

 

[Gilang]

I suggest the developers hire the guy behind Citybound. His Work-in-progress game provides a very very nice game mechanics regarding to road building. I read his development blog about half a year ago and I found it is very cool implementation.

He has implementation in merging lane, intersection control and AI, traffic light, etc. Has anyone here actually ever mentioning Citybound?

Check his development blog at http://blog.cityboundsim.com/. I think it is amazing.

 

[ali.usman]

Regardless of my previous comment in which i stated that the traffic related problems can be fixed with better management i think i am pretty much stuck. The problem is i placed 6 lane roads all over my city but traffic AI does not like any other lane then most right one regardless if its one way or two way road. They can use all 3 Lanes on 6 Lane road (2 way) but they decide to use only 1 lane regardless if the road after interchange is 6 lane as well.

Not sure what to do.

 

[Imgran]

I beg to differ with your statement as you are hypothesizing that thru-put would not alleviate the problem.

The problem, as such, is that the through-put of your roadway isn't always increased simply by increasing the number of lanes. Your throughput isn't as good as you think it is. Period.

Generally speaking I find that roadways that have the one lane stacking problem are roadways where the designer is trying to have far too much control of exactly where the traffic goes. The best solution to traffic problems is not one big road, it's a large suite of much smaller roads that allow excess traffic to bleed off and head towards its actual destination rather than getting stuck going far out of its way so you can get your jollys watching the little cars go round the usually-unnecessary traffic circle.

It really is true that traffic flows better the LESS control you try to have on it. The only time I've tried to seriously manipulate traffic flow is when I've installed a few very short one-ways to force traffic to let an off ramp or overpass drain properly and divert that traffic back into the secondary road networks where it melts away into the grid. And I'm currently running a grid-city of 100,000 inhabitents with zero major traffic issues..

 

[Imgran]

Regardless of my previous comment in which i stated that the traffic related problems can be fixed with better management i think i am pretty much stuck. The problem is i placed 6 lane roads all over my city but traffic AI does not like any other lane then most right one regardless if its one way or two way road. They can use all 3 Lanes on 6 Lane road (2 way) but they decide to use only 1 lane regardless if the road after interchange is 6 lane as well.

Not sure what to do.

The solution here is to create more options for the cars. Sounds to me like you have a lot of traffic that's only differentiating its path after the point where you see it jam up. In a city full of destinations, that means your road options aren't diverse enough to stop broken pileups from happening where most of your town needs to be in exactly one lane to use the road network you've designed to get to where they actually want to be..

If you've got everything in one lane on a 6 lane road, what you have is a 6 lane that should never have been more than a 2 lane. 2 lane roads in this game have the advantage of not using traffic lights, which means they drain quicker and jam up less frequently. Place a grid of interconnecting 2 lane roads and the only time you'll have a major issue with traffic is when a natural bottleneck forms, such as entering or exiting the freeway or passing over an overpass or bridge.

This advice is, of course, not going to be welcomed by those who feel that the most practical possible solution needs to give way to their own personal sense of artistic integrity, I understand that actually, but it's the truth. The grid is win in Cities: Skylines. It's what the AI is built around and it's why there's plenty of tools around to help you build a perfect grid.

 

[ali.usman]

The solution here is to create more options for the cars. Sounds to me like you have a lot of traffic that's only differentiating its path after the point where you see it jam up. In a city full of destinations, that means your road options aren't diverse enough to stop broken pileups from happening where most of your town needs to be in exactly one lane to use the road network you've designed to get to where they actually want to be..

If you've got everything in one lane on a 6 lane road, what you have is a 6 lane that should never have been more than a 2 lane. 2 lane roads in this game have the advantage of not using traffic lights, which means they drain quicker and jam up less frequently. Place a grid of interconnecting 2 lane roads and the only time you'll have a major issue with traffic is when a natural bottleneck forms, such as entering or exiting the freeway or passing over an overpass or bridge.

This advice is, of course, not going to be welcomed by those who feel that the most practical possible solution needs to give way to their own personal sense of artistic integrity, I understand that actually, but it's the truth. The grid is win in Cities: Skylines. It's what the AI is built around and it's why there's plenty of tools around to help you build a perfect grid.

Very interesting though, i like it. Here is a fact though, my traffic hardly jams, the traffic is running but slowly due to only one lane being used. If i open traffic viewer its almost green everywhere and little orange in fewer areas such as these where only one lane is being utilized.

I will try to put a screenshot here

 

[Imgran]

Yeah I've been there too, but if it's running slowly you could be only one poorly timed mass of trucks or one new neighborhood in the wrong place away from bigger issues.

 

[FX2K]

....During development we tried having cars use all lanes and just switch to the one they really want very late, but that created a HUGE mess, the turning cars blocked two lanes and didn't let cars behind them proceed. The one lane queue looks funny, but actually works quite well. Even if the cars would be on all lanes, they could not all fit to the street they are going, so the traffic jam still tells you of something being wrong with your road system

I would love to see this as a mod / option. It sounds a lot more realistic.

 

[dodanek]

I'm not going to join the discussion about the quality of the traffic AI anymore. I'll just leave this screenshot in here for people who want to fix their traffic problems instead of / before waiting for a change in the AI behavior. Here's how the AI works, and how you can use this to your advantage (works on a smaller scale as well).;

Guys, I really love the game and partially accept some of the opinions written in this thread. But I'm sorry: if you don't see how this IS broken, your brain has already been altered by computer games. This isn't how real city life works, and CSL is a city life simulation. It should work like this: http://imgur.com/7xi0ALT, allowing cars going left/right to use both side lanes, with cars going straight preferring to use the two in the middle. In case of no traffic, they can sure use the side ones as well to go straight. But there is literally NOTHING right in forcing players to do the unnatural stuff that is shown on this screen, creating short two-lane pieces just to force the crossroad before to have the directions right. It is nowhere real realistic and it's such a huge game-breaker for me that I even registered here to post this. Insisting that this is a design choice and not a bug worth fixing is creepishly beyond my comprehension.

 

[Azurespecter]

IF it's not possible to mimmick more human like behaviour of lanes then we need more road tools. I'm pretty sure CO have told us such tools are inbound right?

It's a goal of CO to both improve traffic behavior, AND give you more road tools. However, technical support, bugs, and then tunnels and W2W buildings are what's on the task menu right now.

 

[NZSimplicity]

Well maybe I was just lucky or something, but I had a problem at my trees district with traffic, no matter what I did to the roads didn't work...
Then I had the bright idea, what if I deleted my bus routes and do a subway instead...
So I tried it, deleted all my bus routes, then made a subway system and traffic over halved in my trees district..

 

[IVIaarten]

Well maybe I was just lucky or something, but I had a problem at my trees district with traffic, no matter what I did to the roads didn't work...
Then I had the bright idea, what if I deleted my bus routes and do a subway instead...
So I tried it, deleted all my bus routes, then made a subway system and traffic over halved in my trees district..

It's often smart to not put your bus stops right on the main through-road of a district. If you get 2 or more buses queued up for the stop they block a lane.
Also, avoid putting bus stops right in front of intersections. The bus will try to merge right into the row of cars that's already waiting there, hindering flow.

Managing you bus routes effectively is a puzzle in it self

Or you can always go for something like this: