Highway Traffic Merging Problems

[JaySeeEl]

I know this topic has been beaten to death already. I understand the cars will go from point A to B using the shortest, quickest route.

I have a stretch of 3-lane highway that goes out of my city with a couple of right handed ramps further down the road.

I've reach a population of 80k and all of a sudden they are now merging and snarling traffic for reasons I do not know. I tried using the traffic manager to fix, but cannot. I've used different roadways to fix and different configurations, but the same problem persists. I'm at a standstill now that I have an issue I cannot fix.

I've tried numerous things and read discussions and watched videos and cannot seem to alieviate this problem. Please see the video.

Any suggestions on how to fix would be greatly appreciated. Thank you.

https://www.youtube.com/watch?v=t67SEBDwBp8

[Aturchomicz]

Originally posted by Tyrant:

I know this topic has been beaten to death already. I understand the cars will go from point A to B using the shortest, quickest route.

I have a stretch of 3-lane highway that goes out of my city with a couple of right handed ramps further down the road.

I've reach a population of 80k and all of a sudden they are now merging and snarling traffic for reason I do not know. I tried using the traffic manager to fix, but cannot. I've used different roadways to fix and different configurations, but the same problem persists. I'm at a standstill now that I have an issue I cannot fix.

I've tried numerous things and read discussions and watched videos and cannot seem to alieviate this problem. Please see the video.

Any suggestions on how to fix would be greatly appreciated. Thank you.

https://www.youtube.com/watch?v=t67SEBDwBp8

yeah you need to use traffic maneger for that

[Corran]

Can you show a screenshot of the ramps that are further down the road?

[JaySeeEl]

The merging problem is upper left.

https://steamcommunity.com/sharedfiles/filedetails/?id=1554921145

I uploaded the whole city too. Not sure if I did it correctly.

https://steamcommunity.com/sharedfiles/filedetails/?id=1554927916

[FlameWar]

From the looks of it that lane merging problem is due to how the Ai calculates the lane it needs comapred to the next couple of on/off ramps, but the exact workings can be finicky and long to explain.

There should be somewhat of a fix for you tho, if you are willing to use mods.
Get Traffic manager: president Edition and fire up your save. Go to the location where the merger occurs, and select the traffic light tool from TM:PE. The create a timed traffic light ON the highway, right before the problematic spot, and input green/red cycles for all lanes differently. Form your video there's only 2 lanes in use anyways, so you can make 2 cycles:

1- left and right lane green, middle red
2- Middle and right side green, left red

The vehicles will still want to merge lanes, but now they'll do it in droves, first from the elft lane, then midd lane and vice versa. Thsi will lead to the lane emrging to become 2-5 times as efficient.
It won't fully remove the problem itself, but reduce it to such a small delay overall that it basically fixes it.


Edit:
Looking at your screenshot, the problem is with the way/amoutn of on/off rmaps you set up, and the wa yhte game handles lanes on highways.

basically the only cars in the right lane are the ones that want to take the next exit, otherwise they'll all go to mid or left lane to make room for oncomming traffic. And all vehicles that don't want to take the next exit after that will generaly stick to the left lane, so since you got 4+ on/off ramp combos there msot of the vehicles will stick to the lef tlane most of the time.

The bunchign up of the vehicles comes from the fact that they reach the designated stretch for merging lanes concerning the upcoming on/off ramps there, and if your left lane is already to full they will go to the end of that stretch before they can switch lanes, and then wait in palce till they can merge. Which elads to a buildup of cars, which then merge clsoe togetehr, which slows down traffic on the left lane etc.
basically the massive inefficiency of the games lane merger system creates the problem oyu are facing. However, the tarffic-light solution I described will greatly increase the efficiency fo the lane emrging, greatly reducing the problem again.

[MarkJohnson]

Originally posted by Tyrant:

I know this topic has been beaten to death already. I understand the cars will go from point A to B using the shortest, quickest route.

I have a stretch of 3-lane highway that goes out of my city with a couple of right handed ramps further down the road.

I've reach a population of 80k and all of a sudden they are now merging and snarling traffic for reasons I do not know. I tried using the traffic manager to fix, but cannot. I've used different roadways to fix and different configurations, but the same problem persists. I'm at a standstill now that I have an issue I cannot fix.

I've tried numerous things and read discussions and watched videos and cannot seem to alieviate this problem. Please see the video.

Any suggestions on how to fix would be greatly appreciated. Thank you.

https://www.youtube.com/watch?v=t67SEBDwBp8

The simple answer is you created the traffic and it has overloaded the game to manage it. The AI is ppoor as it takes too much power to make it smmart.

Instead, you are tasked with managing your city traffic. The easiest way is to get traffic off the road. Freight is usually the worst offender as exports create a lot of traffic. Try to eliminate exports are you'll be much better off.

Road desiign will help. You need multiple roads to acess your districts. If you have only one or two interchanges into your districts, they can become clogged.

Also, growing cities generate traffic from gaining levels and allowing more cims for each building. This calls in more and more vehicles as your city levels up. I play at x3 speed at all times to help reduce this influx of traffic. A lot of times your traffic will clear up on its own with a little patience.

If you upload your save game, we can see it in motion first hand and then we can better offer advice to solve your issues, rather than playing 20 question and guessing what your problems are. Plus it's much quicker resolution.

To share your saved game, go to the game's main menu, click content manager, then click savegames, then find your problematic saved game and click the share button (make sure it is set to public), then post the link address here.

[ancienthighway]

Have you tried using a collector lane? I'd start it before the bridge, 2 lane highway, that runs parallel to the main highway and rejoins it after the last of the exits. All exits and entrances to the highway would use the collector lane, removing any need for the main highway traffic to change into the far left lane.

You could even take the collector lane a step further and change it a 1 lane between the off ramp and the on ramp at each interchange. The right lane would only be used by vehicles taking the very next exit.

[JaySeeEl]

Originally posted by FlameWar:

Looking at your screenshot, the problem is with the way/amoutn of on/off rmaps you set up, and the wa yhte game handles lanes on highways.

basically the only cars in the right lane are the ones that want to take the next exit, otherwise they'll all go to mid or left lane to make room for oncomming traffic. And all vehicles that don't want to take the next exit after that will generaly stick to the left lane, so since you got 4+ on/off ramp combos there msot of the vehicles will stick to the lef tlane most of the time.

The bunchign up of the vehicles comes from the fact that they reach the designated stretch for merging lanes concerning the upcoming on/off ramps there, and if your left lane is already to full they will go to the end of that stretch before they can switch lanes, and then wait in palce till they can merge. Which elads to a buildup of cars, which then merge clsoe togetehr, which slows down traffic on the left lane etc.
basically the massive inefficiency of the games lane merger system creates the problem oyu are facing. However, the tarffic-light solution I described will greatly increase the efficiency fo the lane emrging, greatly reducing the problem again.

Just for laughs I deleted all the on\off ramps further up the highway and traffic instantly improved and the problem went away. I had no idea the ramps could have such an impact how the cars react so far away from them. I will try some of the solutions in this thread. I did upload the saved game in a previous post. Thank you guys for the feedback.

[FlameWar]

Originally posted by Tyrant:

Just for laughs I deleted all the on\off ramps further up the highway and traffic instantly improved and the problem went away. I had no idea the ramps could have such an impact how the cars react so far away from them. I will try some of the solutions in this thread. I did upload the saved game in a previous post. Thank you guys for the feedback.

The distance the Vehicles will split into the lanes for the next intersection is based partyl off the speed limit for the road they are on.
So on a highway you will get roughly 2-3 times the distance for preparation as on a normal 2 lane road. And since you already need to get them at a noticeable distance on those roads...

Fun tidbit on the side if you are experimenting with lane and junction behaviour: Always build the main connection to your district, or to a cargo train station or such away from any other junction. The game only allows as many cars past the junction as will jit o nthe stretch of road to the enxt junction, so if you can only fit liek 5 cars between the main junction and the next you iwll have constant stop-and-go, even if ther eis no traffic on any other direction.
Oh, and if you build cargo rail (VERY usefull to splti of your cargo transports, both inner city and to the outside) to reduce traffic, build a 'traffic sponge' for the cargo terminal (a traffic sponge is basically a set of curved roads, just liek what you see i nreal life to go up step mountains or such). It will make the traffic to and from the temrinal smoother, up the capacit yof the temrinal, AND make the traffic imapc tother district trafifc less :)

[MarkJohnson]

Your city is crazy jammed up everywhere for multiple reasons.

You have ore industry zoned, but no ore resources in the ground. So, it doesn't create ore products, instead it in importing the ore then returning the truck, then processing the ore and sending deliveries. Then exporting the ore because none wants the ore aas there is no generic industry close by that needs it. This is a heck of a lot of traffic on its own.

You have a lot of spaghetti intersections that delay traffic, plus a lot of these roads are too short and cause vehicles to stop and wait for other vehicles. There should be no cross intersections on the highway. It should flow smoothly without stopping.

You have isolated districts that need interactions from other districts. Connect all districts together to allow traffic to move from district to district.

Remember, cims are on a timer for deliveries, so they need to get places quickly.

Also, ignore commerce. It is not needed in the game and will create too much traffic. If you create commerce, it will request industry to feed it, Then industry will demand commerce as it needs to deliver freight. You will get in a vicious circle and freight will be clogging your roads.

Just build commerce where you want it, then only build offices for employment demands. Offices count as industry, so you need to watch only resisdential and industry demand.

Then when you want commerce, then you can build industry where needed near commerce. Commerce and industry should be on the highway to get deliveries in and out quickly. and next to each other for quick deliveries as well. I often have commerce on one side on the highway and industry on the other and connect them with the 4 leaf clover. two side for the highway to pass through, then the other two sides to connect commerce with industry.

I often make overpases across the highway in spots to make deliveries if it starts getting too backed up.

[Apples]

Some dodgy fixes i use as i'm mid way between building is creating a weird untidy bypass that allows them to feed into the lane they are curreently merging into. So if they are trying to feed in the left lane there, i'd create a dodgy over pass and connect to the left side of the highway, from where those specific set of trucks are coming from.

Most of it is watching where that set of traffic is coming from and going to, and trying to spread it out a bit. It's all trial and error. :)