Yield mechanics

[Shiggs]

Curious what is going on here. I think I have isolated a fairly serious issue with the traffic AI.

I have to wonder what in the world is going on here. Why are they stopping? They should be yielding at least, if not just driving straight through without a thought. That roundabout is all highway and ramps. Furthermore, an identical intersection immediately north of there they are just driving straight through....?

 

[BlackViper.com]

I touched on this in this thread as well, but your video is pretty good. I would like to know what is going on as well. See picture 3 in my thread about my roundabout with a 3 lane highway and a two lane two way. The right lane has priority and blocks up everything for me. But in your case, the AI might be getting confused with the train tracks above and might be yielding to that. I have not used any tracks, so I cannot comment on its behavior, but I have read that some mods might mess with traffic AI.

https://forum.paradoxplaza.com/foru...ne-has-priority-how-to-work-around-it.847425/

 

[FireFlowerist]

Curious what is going on here. I think I have isolated a fairly serious issue with the traffic AI.

Encountered this behavior today in my city and the problem is you have. The thing is you have "intersection" so small that when one car is there others will wait until it has entered it or crossed it. I can't remember did this exist with old 1.06b patch because I haven't builded this small roundabouts during that time.

 

[BlackViper.com]

Encountered this behavior today in my city and the problem is you have. The thing is you have "intersection" so small that when one car is there others will wait until it has entered it or crossed it. I can't remember did this exist with old 1.06b patch because I haven't builded this small roundabouts during that time.

This is it. Yes, the intersection is small and cannot fit more than one truck, so if a car is "under" the rail system, the traffic behind will stop because they do not have enough room to continue. If a truck is there, the cars will stop. Notice in the middle two cars go forward as their was enough room for both of them.

 

[BlackViper.com]

I should say that each time two cars would go forward, but a truck and car or two trucks would not as not enough room. Nice catch FireFlowerist, but I do believe this is how it worked since retail.

 

[Shiggs]

this is very weird. I've watched this intersection for a while now. Immediately after posting this thread, got back in the game, cars are flying through there at 100kpm, traffic completely clear. Come back a little while later, huge line of traffic all cars are stopping again, nothing had changed. I am using exactly 1 mod, the fine road heights mod, so I doubt it is anything to do with that.

I think you are right Fireflowerist, it has to do with the distance between them, but it still doesn't make much sense, they really shouldn't even consider stopping. Even weirder, the cars in the right hand lane, the only ones who should have to consider merging traffic, always fly right through, going straight or turning right.

I'm curious if making the transition smoother (hence allowing a higher speed) would tidy things up enough to remove it... I'll try it and re-edit my post later.

 

[BlackViper.com]

I think you are right Fireflowerist, it has to do with the distance between them, but it still doesn't make much sense, they really shouldn't even consider stopping.

It is because the AI does not want to block the intersection, even though they do it all the time. I think it might be to do with stop light behavior as well. Yes, I know no stoplights are here, but they cannot continue into the intersection if their is not enough room "because" a stoplight might be there and they would block the intersection behind them (cross traffic). So, it looks like they are yielding to no traffic when they are just stopping because of not enough room ahead.
Hope that is clear as mud.

 

[ItalianGuy]

I agree with blackviper and must add that this is a simulated legal behaviour, not a bug. To avoid those stops, distance intersections so that a truck can fit between them.

 

[BlackViper.com]

I also believe that if those roads were one way "out" of the roundabout, the AI would know it is not possible to have a stoplight there (yes, I know, no stoplight is actually there, but it could be if that was a crossroad), so the cars/trucks would continue, possibly blocking traffic behind them, but it would not be "cross" traffic, so that is OK.
Hope that is even more clear as mud. LOL!
Also, CO has said many times that close intersections are a bad thing.

 

[Shiggs]

what I am saying is a highway or a highway ramp should override that. It is a simple rule of the road everywhere in the world. The entire point of a highway is to keep moving.

Don't get me wrong, I can fix the problem, already did actually, just made the bridge for the railroad longer, removed that intersection and connected it to the road/intersection that was behaving correctly.

The behavior is not consistent. That in of itself is a bug I'm afraid. Like I said in my previous post, one minute they are flying though not stopping, the next they are. Its changing behavior mid simulation.

 

[BlackViper.com]

what I am saying is a highway or a highway ramp should override that. It is a simple rule of the road everywhere in the world. The entire point of a highway is to keep moving.

Unfortunately, one can use all kinds of roads in game that is generally not the way they are used in reality.

True "6 lane, two way, separated median" freeways with full freeway speeds (65/75/85 MPH) do not generally have two lane roads intersecting them (usually over pass or underpass), they have off ramps and on ramps and if they do have cross traffic, a stop light is there with massive signs and warnings before one gets to that point (and usually not full freeway speeds due to being in a small town and no cloverleaf). If the cars are merging, a merging lane is provided (usually) and that is not provided in game.

I am sure someone can google maps a spot where that is not the case, but I am pretty sure it is rare, at least in the US.
So if one is using roads as they are not really intended, as in this case, a very small roundabout with "freeway speeds", with intersecting traffic coming from two lane two way roads, it just does not happen IRL and I feel the game cannot be blamed for misuse of a road tile.

Just my opinion, but I understand where you are coming from.

 

[Shiggs]

yes, and I understand your points and can work around the game mechanics as such. LOL, yes I am using a highway the way it should not be used, but only because the game as you have already hinted at cannot recognize the difference between a connecting road and a true cross traffic intersection. It was my attempt to make the roundabout more efficient.

Once we have the transportation mod and you can actually make them yield where they are supposed to and stop where they are supposed to in a round about, we can use 1 way avenues like would be used in real life.

 

[Person012345]

What I have found is that often if the AI can't "fit" in the next section of road immediately it'll stop. So where there should be a continuous flow of traffic through a small "section" of road (between two intersections) instead, say a tractor goes, the next car decides that the tractor in front has taken up all the space in the next section and so to avoid blocking up the intersection it stops even though the tractor keeps moving and the space is perfectly free. Then the car goes and maybe another one goes but the lorry behind them decides it can't fit so it stops. etc.

 

[bluespottedhors]

That is the oddest traffic circle I've ever seen. Traffic circles in the real world have the same amount of lanes all the way around!

 

[Shiggs]

That is the oddest traffic circle I've ever seen. Traffic circles in the real world have the same amount of lanes all the way around!

well it did start out all as the one lane ramps, but I upgraded part of it to try to keep them from stopping. I even cut out half the circle and redrew it, and tried attaching the road just a little further away, it still didn't work... the things we come up with lol.

 

[Jenkins87]

It is because the AI does not want to block the intersection, even though they do it all the time. I think it might be to do with stop light behavior as well. Yes, I know no stoplights are here, but they cannot continue into the intersection if their is not enough room "because" a stoplight might be there and they would block the intersection behind them (cross traffic). So, it looks like they are yielding to no traffic when they are just stopping because of not enough room ahead.
Hope that is clear as mud.

Even though this doesn't "read" well, you did a great job at explaining something I have been trying to explain to several people for a while. In Australia it is illegal to be the "last car" in the jam if your car is going to be still inside the intersection after you've come to a stop. People ignore this all the time IRL and it is very dangerous, but essentially I chalked up the AI in the game doing the same thing, which you explained well.

That is the oddest traffic circle I've ever seen. Traffic circles in the real world have the same amount of lanes all the way around!

Well, it depends on what the roundabout (traffic circle as you call them) is actually there for. Here is Australia, our roundabouts are plentiful, but they are as you say, mostly the same amount of lanes in and out. That isn't a rule though, because even locally, there are roundabouts that have 4 lanes for 180 degrees of the roundabout, and the other 180 degrees has a strange mix of 3x3 lane feed in and out roads, and 1 particular lane coming from one of the 4 actually has traffic lights to stop it from continuing around the roundabout. Confusing to explain, just as confusing to navigate through in a car IRL lol, it also banks up in morning and afternoon rush hour really bad. Sometimes for several kilometres back from that roundabout.

 

[Myquandro]

Solution for these thing is simple, make roads big enough in distance don't try to fit everything in tiny spaces. This goes for roundabouts and every other type of road.

As for roundabouts with varying amounts of lanes. Here in The Netherlanfs roundabouts seem to be the next big thing if it comes to road design and have been for many year. I have driven a handful of different types roundabouts (turbo-roundabouts, standard ones, multilane-roundabouts, roundabouts with overpasses, bypasses, through passes, highway interchanges that are roundabouts, double roundabouts, etc.) I have seen several of these also having two lanes for one part, one lane for another, bypass in one direction, etc. it looks weird in game because lanes don't merge and continue properly like on highways, but the idea of multiple lanes on one part isn't weird.

 

[StefanoSkylines]

Roundabouts ARE bugged.
What I experienced is this: in real life, cars in the roundabout do have the priority, in this game not, even with mass transit option that adds the stop sign for adjacent roads.
No matter how many lanes in/out the roundabout, the yeld is not in the roundabout.

 

[Person012345]

That's not so much of a "bug" as the fact that they never really programmed that logic in. A car doesn't know that a roundabout is a roundabout. AndIdon't blame them really because I've never really seen a commecial game where the AI actually understands roundabouts properly.

Though you should be using highways/onramps for roundabouts, never use ordinary roads.

 

[Vimes]

Holy necrosis Batman....!

What is it with these ancient necrotic posts being ressurected of late...?