Cars using shortest routes instead of fastest?

[NineLine]

I'm on the last campaign mission (Shanghai) and I connected all cities with highways. I built the highways like a circle around the cities with several on- /off-ramps to avoid congestions. But nevertheless the cars only use one off-ramp and start to jam the complete highways, while not using the other highways at all.

Do cars only use the shortest routes? Even if the route is jammed? It would be much better if cars would use the fastest route (measured by time) instead.

Any idea how to solve the mess on screenshot?

https://steamcommunity.com/sharedfiles/filedetails/?id=1986701621

[Berd0]

Of course they use the shortest route. If you want to go from one city to another, would you enter the ring road at the other side of town rather than at the section closest to the other town? I wouldn't build ring roads this extreme, only when you have a city with multiple highways leading out of it 3+, and even still it, most cars passing through one city's ring road will want to skip that particular city and go to the next. That's what ring roads are sorta for also, to divert traffic from the centre to the edge.

For your problem I would simply build multiple country roads (2 by 2) ones in between the cities as they're so close togheter. And that way get rid of the bottleneck

[Martin]

You need to force the people to go the longer routes. You can do this using shorter narrower streets and bus lanes. Cars will then take a different route because the short route is no longer the fastest.

[neldot]

To be more precise, they roughly calculate the time needed for different routes (but they seem to not include traffic jams in this calculation), and then they chose the path that takes less time. As Martin said, using the tools at your disposal, it's pretty easy to force them to use a certain path.

[Starbucaneer]

Originally posted by Berd0:

Of course they use the shortest route. If you want to go from one city to another, would you enter the ring road at the other side of town rather than at the section closest to the other town? I wouldn't build ring roads this extreme, only when you have a city with multiple highways leading out of it 3+, and even still it, most cars passing through one city's ring road will want to skip that particular city and go to the next. That's what ring roads are sorta for also, to divert traffic from the centre to the edge.

For your problem I would simply build multiple country roads (2 by 2) ones in between the cities as they're so close togheter. And that way get rid of the bottleneck

In real life My Partner does lol. Drives me mad (Pardon the pun).

[NineLine]

I do that too when i know that on the shorter route is big traffic jam :p

Thats why my navigation system always calculates the fastest route. That route that costs less time.

But thanks for hints. I will try them.

[joeball123]

Originally posted by Berd0:

Of course they use the shortest route. If you want to go from one city to another, would you enter the ring road at the other side of town rather than at the section closest to the other town?

When maximizing route efficiency, I would normally take the shortest route by expected travel time, which is not necessarily the shortest route by total travel distance. If where I want to go is on the far side of the city, it is entirely possible that I would prefer the far-side ring road entrance to the near-side ring road entrance - especially since ring roads in the real world often have lower speed limits than major highways, are more likely to have controlled intersections, and probably have heavier traffic due to their likely-greater share of local commuter traffic as compared to a highway that largely bypasses the city. Additionally, depending on where exactly I'm going in the city, I might not want to get on the ring road at all; possibly there is a better exit to take from the highway than either the near-side or the far-side ring road entrance.

Moreover, the routes real people take are affected by intangible factors - maybe I just like cruising down the highway at about 70mph (113km/h) better than I like driving in town, maybe the views along one road are in my opinion better than the views along another, maybe the more efficient route passes through a bad part of town or has negative associations for me personally, maybe I don't have perfect knowledge of the area and so am taking a route that I know instead of a more efficient route with which I'm unfamiliar, maybe I prefer to drive along less-trafficked side streets and back roads than along more-trafficked main roads. Real people do not make decisions solely on the basis of maximizing efficiency, at least not solely by tangible efficiency metrics like travel distance and travel time.

[yanico]

If U were not opening that topic, I've been forced to do it myself! One for sure has to fasten the speed limit to solve that problem. I'm just really shocked, about how much basic failures like that the game was released with!

[Berd0]

Originally posted by joeball123:

Originally posted by Berd0:

Of course they use the shortest route. If you want to go from one city to another, would you enter the ring road at the other side of town rather than at the section closest to the other town?

When maximizing route efficiency, I would normally take the shortest route by expected travel time, which is not necessarily the shortest route by total travel distance. If where I want to go is on the far side of the city, it is entirely possible that I would prefer the far-side ring road entrance to the near-side ring road entrance - especially since ring roads in the real world often have lower speed limits than major highways, are more likely to have controlled intersections, and probably have heavier traffic due to their likely-greater share of local commuter traffic as compared to a highway that largely bypasses the city. Additionally, depending on where exactly I'm going in the city, I might not want to get on the ring road at all; possibly there is a better exit to take from the highway than either the near-side or the far-side ring road entrance.

Moreover, the routes real people take are affected by intangible factors - maybe I just like cruising down the highway at about 70mph (113km/h) better than I like driving in town, maybe the views along one road are in my opinion better than the views along another, maybe the more efficient route passes through a bad part of town or has negative associations for me personally, maybe I don't have perfect knowledge of the area and so am taking a route that I know instead of a more efficient route with which I'm unfamiliar, maybe I prefer to drive along less-trafficked side streets and back roads than along more-trafficked main roads. Real people do not make decisions solely on the basis of maximizing efficiency, at least not solely by tangible efficiency metrics like travel distance and travel time.

Yea this makes sense. But computers just solve a basic optimization matrix either for total (of the whole system) travel time or cost, or either personal travel time or cost (cost is both time and distance). I don't know wether the game optimizes for the total or the individual vehicle, which makes a big difference. Therefore, assuming it's individual, the ai will more often the shortest route.