Turning Lanes at intersections

[Bub]

In the United States, turning lanes are a modern invention at intersections. For example, in historic cities turning lanes are not used because there is not enough room to implement them.

[sdog]

Is this posting of an informational nature, telling us that there is a thing like turning lanes?

Thank you! There must be hundreds of people here -- living in places with mud paths and ox carts only -- who learned this exciting new thing.

Or is it a suggestion to implement this in the game, perhaps you would like to explain what it would be good for in the game. Why it ought be done, and how it could be implemented. Else your posting is of similar use as in the other case, i thanked you for above.

[Bub]

Turning Lanes are used to not delay traffic turning onto another road with continuing traffic in front

[Ters]

We also know that.

[Fabio]

In game it could be useful for left-turning vehicles not to block the vehicles behind in case of heavy traffic in the opposite lane. While I thought of it myself several times, I fail to see how could it be done. Maybe left turning vehicles should shift to the middle of the road (more or less where tram tracks are-- but then this behavior should be avoided when tram tracks are present) and the other vehicles could pass them straight on their right... A turning lane could be possible instead for 4-lane roads if ever implemented like in Isidoro's model.

[Ters]

The way yielding works in Simutrans also somewhat reduces the problem that made turning lanes useful.

[Fabio]

True, Ters. Simutrans doesn't have a road hierarchy.
I wonder if making slower roads yield to faster ones would work well and be possible to implement.

[Ters]

I would assume that would run into the same difficulties that have prevented vehicles from matching its speed to the slower vehicle in front. However overtaking has overcome similar hurdles.

[mEGa]

Could have possiblity to force road hierarchy with signals ?
I notice, for example, that limit speed signal on pak128 doesn't work very well.  Sometimes slow cars appear between signals (in the intersections) and turn over being in the way of other vehicles.
Also, it is not possible to force certain vehicles to go by highway around cities rather than the streets of the city center, except put no-entry sign (-)
Thus create traffic lights for streets would not really offer improvement?

[Ters]

I think the basic problem is that vehicles have a very limited awareness beyond the immediate vicinity. A vehicle could approach a yield sign, see that the next tile is free and start driving, only to end up in the way of a faster vehicle that was still several tiles away at the time.

Also, it is not possible to force certain vehicles to go by highway around cities rather than the streets of the city center, except put no-entry sign (-)

There's waypoints.

Routing could, and maybe does, prefer high speed roads to low speed roads, and I also seem to remember that it avoids congested areas. However, since vehicles still have a stricktly distance based running cost, going around could make an otherwise profitable line unprofitable. It would therefore only work for lesser detours, not circling a big city.

[Roads]

I was going to suggest waypoints until I read Ters' post.  The waypoints are a gem that has MANY useful applications.

[Ters]

But they can also be a nightmare to maintain.

[Fabio]

Additionally, way points are not too intuitive and easy to get for beginners.

[Roads]

Aww Fabio, I'm still a beginner really but no doubt people brand new to the game would likely not be thinking finer points of strategy and IMHO, way points and the sign are the two most strategic elements of the game.  Of course I've got a lot to learn yet.

[Bub]

Is this topic still focused on turning lanes?

[Ters]

No, but we know about them. It's just a matter of waiting for a developer willing to set of a lot of precious spare time to make this work in any meaningful way. I wouldn't hold my breath, as there are lots of other things to work on.

[IgorEliezer]

^ First of all, the developers need to implement the one-way-multilane feature before implementing "turning lanes" or anything "lane-dependent" feature, and I can advance to you that it hasn't been so easy implementing... I don't know how it is going now.

[Bub]

It wouldn't mean a one way road, it would mean a widened road at the intersections.

[An_dz]

And Igor said that if you want a three lane road (what a Turning Lane is) the Simutrans engine first needs to understand what a lane is, because right now the code makes Simutrans only understand this is a road, and the code don't know anything about the road lanes, that's why when you create a one way road cars only travel in the right lane.

So when Simutrans engine understand what a lane is we can start thinking in create such things.