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

[stumason]

Alienate 90-95% of the player base just to plan your road a few intersections ahead? Really? I think you're just pulling numbers out of thin air, there.

It isn't really that hard even though you are making it sound like a Herculean feat. All I find is needed is to watch how the traffic flows (from-to) and adjust accordingly.

If you have large amounts of traffic passing down a road, where is it coming from and where is it going?
Is it causing traffic to back up and have a knock on effect?
Can you divert traffic around that choke point?

For example - I wish I had pictures of my city now - I had an industrial park on one side of a Highway (with a 6 lane OW system) and a large residential zone the other, with commercial zone (with it's own OW system) adjacent to it separated by a 6-lane OW circular system. This worked fine, at first, but as the city grew, so did the traffic load. Before long, I had traffic backing up at the OW ring road from the highway and ramps as trucks would come from the industrial, into the commercial then try to go back again.

I then realised that the intersections were the root cause of the backing up on both sides of the highway. Off the OW systems were smaller roads to feed the city and it was here traffic was clogging up. On top of that, I also realised the big difference in speed between the highway and 6-lane roads. With this in mind, I built an elevated highway going in one direction which connected to both highways from the outside world - scooping up trucks. This then was directed into the heart of my industrial zone and fed smoothly onto the 6-lane OW system, then transitioned at the other side back into an elevated highway to go to my commercial and residential zones, with ramps to drop traffic off into their own respective road systems until it came back around to where it began, completing the loop.

Now, I don't get traffic backing up on one side of my city because of all the trucks trying to get back to the industrial zone through the residential and commercial districts.

As for whether you think nice thoughts about me, I really couldn't care less, but at the end of the day, a little bit of thinking about where your traffic comes from, goes too and how it is to achieve that is enough to rid yourself of almost all your traffic problems.

Sitting there and bitching about whether they take the right lane and how it's an AI problem is just not dealing with the issue - you suck at planning. I know this because I too sucked at planning and I had the problems the OP has showed us he is having. Then I sat and thought about it, fixed it and I do not get the problems you're complaining about now. Traffic flows freely.

 

[Sotrax]

Well, with the possibility to adjust the turning lanes and the ability to forbid turning on some points the traffic could flow really really good even without new road layouts or a major change in the pathfinding mechanics..

 

[stumason]

Well, with the possibility to adjust the turning lanes and the ability to forbid turning on some points the traffic could flow really really good even without new road layouts or a major change in the pathfinding mechanics..

I would like to see a wider variety of roads and road options, like we had in CiM. I think this would also help with traffic issues.

 

[Person012345]

Every single one of these problems in this thread are correctable by just planning your cities better. I saw not a single issue here that would not be solved by better city management.

"But I am the best!" No, no you aren't, not even close. I see your screenshots, they do not speak to your greatness. Instead of a thread about bad traffic AI, this is more like a thread about "Look how foolish and arrogant I am, see, here is proof."

I KNOW how to fix this. I can put a roundabout in at the end there and it works great (the reason the traffic is backed up are the traffic lights, see here: http://puu.sh/gzsZi.jpg). So don't bother telling me how to fix it.

Go work on your reading comprehension and then come back.

 

[Person012345]

I have to agree with those commenting about "poor design". I too had major traffic issues in my city last night - the original set up I had was fine to start with, but soon buckled under the strain of a growing city.

No-one is complaining about having traffic problems.

 

[stumason]

No-one is complaining about having traffic problems.

Actually, they are - they are complaining that all their traffic is backing up in lanes and this is entirely down to the layout of the road. I know this because I've had the same issue, which I fixed by rejigging the layout of my roads, cutting the amount of intersections and building more highways between where the traffic originates and where it wants to go.

Yes, the AI is quirky, no-one denies this, but it can easily be remedied by a little bit of thinking.

 

[kosh22]

Actually, they are - they are complaining that all their traffic is backing up in lanes and this is entirely down to the layout of the road. I know this because I've had the same issue, which I fixed by rejigging the layout of my roads, cutting the amount of intersections and building more highways between where the traffic originates and where it wants to go.

Yes, the AI is quirky, no-one denies this, but it can easily be remedied by a little bit of thinking.

To say its entirely down to the layout is woefully wrong. There is an AI issue here but there is also optimal road layouting as well. But to be blind to the AI issues is quite astonishing.

 

[stumason]

To say its entirely down to the layout is woefully wrong. There is an AI issue here but there is also optimal road layouting as well. But to be blind to the AI issues is quite astonishing.

Who's blind to the issue or even said it is "entirely down to layout"? I have said that the AI pathfinding is quirky (and for an entirely sensible reason - they don't work out the route on the fly to save on computation, they work it before leaving), but can be entirely worked around with some sensible road planning.

 

[Imsvale]

Alienate 90-95% of the player base just to plan your road a few intersections ahead? Really? I think you're just pulling numbers out of thin air, there.

You really think most people are interested in dedicating their previous playtime to in-depth traffic analysis following unintuitive rules? I think not. Therefore I believe it's in CO's interest to make a little tweak, to make traffic rules more accessible, so people to a greater extent can think about what they would do in this situation and see it apply in game as well.

It isn't really that hard even though you are making it sound like a Herculean feat.

My concern is I don't think most people will be interested in going to such lengths, however you grade them. It will take a lot of continuous dedication to studying the traffic in your city, which detracts from your time doing other things. A lot of people have limited time to play (myself excluded, so don't automatically assume I'm in this category), and for them it would be ten times better if they could apply their own thinking about traffic to in-game traffic. For the rest of us, it makes little difference. We'll figure it out anyway.

Sitting there and bitching about whether they take the right lane and how it's an AI problem is just not dealing with the issue - you suck at planning. I know this because I too sucked at planning and I had the problems the OP has showed us he is having. Then I sat and thought about it, fixed it and I do not get the problems you're complaining about now. Traffic flows freely.

Yeah. This is a discussion forum, in case you hadn't noticed. When there are problems, there will be people trying to describe the problem. You want to call that bitching, maybe you shouldn't be on a forum. The fact that some people don't consider it a problem and are more than happy to figure out the quirky behavior is duly noted several pages back. This is not about whether or not it can be fixed in its current form. This much has been pointed out a long time ago. Is that so terribly difficult to accept?

Now. I am quite happy to sit down and follow the little cars around and tweak my road network. If CO decide to leave it the way it is, I'll do just that. Do not make any assumption to the contrary. But I genuinely do not believe the majority of people playing the game are particularly interested in this. I could be wrong, by all means. But this is why I'm arguing this side of the matter.

It is well understood and accepted that poor planning is part of the problem many people are experiencing. You can stop beating the dead horse.

There is an high preference to use only one lane... it's a bug.
You can tell me that the traffic is not well managed by me, and ok, it's my first game so it's possible!! But there is no reason why citizens don't use other lanes in that images.

 

[Mrvise]

hops wrong

 

[stumason]

Thing is, this has been an issue in CiM as well - I doubt there will ever be a solution that will make everybody happy. Yes, you probably could make each Cim constantly re-evaluate the route and for people with high-end rigs, it probably wouldn't affect performance, but for a good many people they don't have big machines, so how would this affect them? CO have said they've had to make compromises for the sake of performance, this is one of them and I highly doubt, no matter what they do, the problem will ever go away.

It's all very well saying "stop beating a dead horse", but isn't that exactly what you guys are doing when plenty of others (myself included) have said you can work out the kinks with a little bit of sensible road placement?

Yes, I went to an extreme and spent 3 hours doing it, but that was largely down to aesthetic concerns and then going on a mission to expand my highway network way beyond simply solving the initial problem. The actual issue was pretty obvious and was easy to solve. I think you're being disingenuous towards other players by suggesting that they neither have the patience or skill to fix it, or that they don't want to trouble themselves with sorting out traffic problems - as a city building game, managing traffic is going to be a major part of it. As I and others have repeatedly pointed out, this "bug" is easily overcome with some mild cranial activity - I am sure most people can cope with this.

 

[barcasam7]

Lets put it straight. This is a game, yes. Bad city planning is hugely detrimental to your traffic. However, the AI has some major flaws when it comes to using the lanes. As this game is a game I think if the AI problem was tweaked it would improve the game and give the users more satisfaction. What is the point of having 3 way roads when traffic only stick to one of the lanes? There isn't and that's the problem. Traffic is an integral part of this game and how your city functions. Yes, challenges are fun, but when a challenge is caused by an AI problem it becomes annoying. Also these AI bugs can be a major factor why players don't get further in the game. To cater for everyone's needs the AI should be tweaked. After all not everyone is a master of road city planning and not everyone wants to be. I don't get how Sim City and Cities XL can get their AI traffic to use all the lanes, but this can't.

 

[Imsvale]

as a city building game, managing traffic is going to be a major part of it.

And no one is on any level insinuating they want traffic to magically resolve itself. But these are unnatural, unrealistic challenges created by what is in your own words indeed a quirky AI. There are enough challenges to be had without this peculiar problem. You know it full well, so can you please stop implying otherwise. And I'd like to be posed with simulated real problems, not artificial and ficticious problems unique to a computer simulation following a particularly rigid logic. After all this is meant to be a city simulator, and by extension, a people simulator, is it not? Is it so unreasonable to ask the traffic to act a little more according to human intuition? Assuming of course it doesn't come with too much of a performance hit; that would again alienate some significant portion of the player base lacking high-end computers. I'm not in favor of that either; I'd rather have the quirky AI.

Can we agree that this situation is less than ideal? Because really, that's all anyone is trying to establish here. And in turn hope that CO is able to find a remedy that doesn't cause a performance meltdown.

For the record, your horse is dead. Ours is not until CO announce their intentions.

 

[Person012345]

Actually, they are - they are complaining that all their traffic is backing up in lanes

No they're not. Even when there are no traffic jams, cars still only use one lane. THIS is the problem. Having traffic jams just mean you can show it in a screenshot. The topic has NOTHING to do with traffic problems.

 

[IVIaarten]

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).;

 

[slornie]

I think this issue definitely comes down to a bit of both sides - road layout design by players and AI logic from the game.

The AI is obviously overzealous/overly aggressive in selecting lanes two or three intersections ahead of where it wants to turn, and that decision made before the agent even sets off on the journey (as has been mentioned this was also the case in CiM/CiM2). But on the other hand, it's also equally obvious that CO have taken this approach - planning the entire route before setting off and not allowing recalculation on-the-fly - for a very good reason, to reduce demands on processor power.

The road design matter will probably resolve itself as players become more familiar with the game and learn the behaviour of Cims and adjust how they build their cities and networks appropriately. For the AI hopefully CO can find the sweet spot in the pathfinding logic which gives us the greatest benefit without too badly hitting performance, but I think rather than sitting here arguing between road design and AI we should be making more of an effort to come up with and discuss possible ways for CO to make those tweaks and improvements, much like is happening in the workers-don't-need-to-go-to-work thread.


My initial input on a possible tweak towards a solution would be to add another variable to the initial pathfinding logic used before setting off:

Give each vehicle/planned journey a different probability of when it will make lane changes. E.g. 40% of Cims might continue to drive as currently they do, taking the optimal lane two or more intersections in advance; then say another 45% of Cims might only change to the optimal lane one junction in advance. The final 15% of Cims would represent those drivers who either don't 100% know where they are going, are impatient or represent those annoying drivers who just cut in and change lane only at the last second before the junction.

While not a perfect solution, and certainly not as dynamic and responsive as I'm sure we'd all like (including CO), I feel it could help to spread out the load across lanes?

 

[darkelf1000]

Or, it could be a thread about how bad the traffic AI is. After about a dozen cities, all with varying degrees of designs made efficient for traffic, it does not change the fact that a turning lane is ideal for heavy traffic. The images I posted of a mile-long line of garbage trucks using one lane to turn on to a 6-lane two way is improper road placement. Who would have thought?

In fact, the problem has existed since Cities in Motion 2. Cities that came with the program were pre-made. This isn't about vanity, this is about traffic issues, which has plagued any game using an agent system. City planning only goes so far, especially for people who aren't interested in reading a manual to draw a few roads. [COLOR="#FF0000"[B]]Building a city the "right" way is not how I would want to build a city every time, this is a city builder meant to take a beating at any city design we throw at it, so we should expect it to perform the same way[/B][/COLOR]. Pathfinding is tailored around most optimal route, and with every agent working on the same agenda it leads to the problems in the pictures posted.
[/COLOR]
A NORMAL driver would not wait for the mayor to optimize the street grid, he would find another street to turn onto. Instead of having cars disappear in heavy traffic, they should just simply re-evaluate their route and find another way, whether it is longer or not.[/QUOTE][COLOR="#FF0000"]

+1

 

[C40LFR]

Did you even bother looking at the pictures in the OP?

Not sure what you're saying here to be honest, but this isn't a question of not enough lanes in this particular case. It's a matter of (seemingly) not using all the lanes that ARE designated for whatever turn they're taking. Again assuming it's not a corner case, cf. my previous post.

I did look at the original pictures. I don't have this problem except for one intersection due to improper planning and design.

Here's my one problem intersection:
http://steamcommunity.com/sharedfiles/filedetails/?id=408040244

The traffic coming off the freeway on the right of the image has two lanes that allow left turn movements, so at face value, it looks like a bug. However, the problem is that all that left turning traffic is making a U-Turn to get on the paralleling freeway to the right because I placed no connector for those movements. Therefore, the AI is making two immediate left turns movements to make the U Turn. The street in the middle has only one left turn lane, so presto, all that U-Turning traffic is pushed into one lane coming off the freeway. Same with the traffic going along the middle of the image. There's only one left turn lane, and the intersections close together are causing a back up. I literally have no other issues in my city except for this intersection.

Now, I'm not saying the conditions are completely realistic, but I certainly don't think it's a bug at all.

The AI is much better in CSL than CiM2 about using all lanes. I simply don't have this problem unless it's due to poor planning. It seems fairly simple to me, though I'm a Civil Engineering Major specializing transportation engineering. FYI, putting down a bunch of 6 lane highways everywhere =/= good planning.

 

[C40LFR]

I did look at the original pictures. I don't have this problem except for one intersection due to improper planning and design.

Here's my one problem intersection:
http://steamcommunity.com/sharedfiles/filedetails/?id=408040244

The traffic coming off the freeway on the right of the image has two lanes that allow left turn movements, so at face value, it looks like a bug. However, the problem is that all that left turning traffic is making a U-Turn to get on the paralleling freeway to the right because I placed no connector for those movements. Therefore, the AI is making two immediate left turns movements to make the U Turn. The street in the middle has only one left turn lane, so presto, all that U-Turning traffic is pushed into one lane coming off the freeway. Same with the traffic going along the middle of the image. There's only one left turn lane, and the intersections close together are causing a back up. I literally have no other issues in my city except for this intersection.

Now, I'm not saying the conditions are completely realistic, but I certainly don't think it's a bug at all.

The AI is much better in CSL than CiM2 about using all lanes. I simply don't have this problem unless it's due to poor planning. It seems fairly simple to me, though I'm a Civil Engineering Major specializing transportation engineering. FYI, putting down a bunch of 6 lane highways everywhere =/= good planning.

Now, here's that same intersection after I rebuilt the interchange and eliminated all the U Turn traffic coming off the freeway:
http://steamcommunity.com/sharedfiles/filedetails/?id=408055581

Jesus, proper planning and design is F---ing magic in this game.

 

[IVIaarten]

Now, here's that same intersection after I rebuilt the interchange and eliminated all the U Turn traffic coming off the freeway:
http://steamcommunity.com/sharedfiles/filedetails/?id=408055581

Jesus, proper planning and design is F---ing magic in this game.

Nice, glad you got it fixed