News:

Want to praise Simutrans?
Your feedback is important for us ;D.

Road with advantage of passing

Started by Icey, August 02, 2013, 09:52:28 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Icey

It would be useful to make a road with advantage of passing, you already put traffic lights in, but to be honest they are not very useful. On the other hand a road with advantage of passing would prioritize your roads, and it would be enough to add a sign on the mentioned road. If anyone else had this idea I apologize.

prissi

Any road is a passing road. But then the cars have to be much faster and with no incoming traffic.

You can find lots of discussion concerning two lanes road in the forum.

Icey

Yeah, I probably expressed myself wrong. Actually I wanted to suggest adding a new traffic sign:
http://autoskola-formula.hr/images/uploads/C008_prednost.jpg

or how about a stop sign?

Ters

You mean right-of-way, not passing (which sounds like overtaking).

I think this is difficult, because I believe vehicles are very near-sighted. They drive if the area right in front of them is clear. Only when overtaking do they try to look further ahead, but this is so difficult that overtaking very rarely can happen. In cities, yields signs will have trouble working due to the density of intersections, which means that a vehicle that is supposed to yield will never see the vehicle it supposed to yield to (that is coming in from another side road) before it is too late.

Another problem is that the yielding vehicle may easily end up yielding forever, unless we also implement impatient recklessness.

Icey

I really do not know how difficult it is to make, but I think it could be a great help (at least I really needed it last time I played). This was only a suggestion, now it is up to you guys to make it happen or just say it is rubish and keep working on other stuff   ;)

Ters

I seem to remember that overtaking was also believed to be almost an impossibility, but someone had a bright idea, so there is hope.

tubanonymous

I believe the choose signal will get vehicles to multiple tiles as a block I think. But that's only with a station. And I still don't know how to incorporate a yield signal into that




sdog

Quote from: Ters on August 02, 2013, 02:37:18 PM
I seem to remember that overtaking was also believed to be almost an impossibility, but someone had a bright idea, so there is hope.
Is this a brainstorming question?
Overtaking appears a much more difficult problem, as cars have to decide it, it is not located to one spot. This is different for the right-of-way problem. Don't solve it for the car but for the intersection.

An intersection with traffic lights, that are always green for one direction, unless a car from the other directions arrives at it, then it switches. Unless there is a car on the tile of the prefered direction.

For an intersection of the form:

  | A |
--     --
B       B
--     --
  | A |

state (i)
green for direction A--A
red for direction B--B

state (ii)
red for A--A;
green for B--B.

  • begin in state (i)

  • If there is a car at either A = 1, if not A = 0, same for B.

  • If B=1 and A=0 switch to state (ii); return to (i) after v seconds

  • If B=1 and A=1 remain in state (i) and start a timer,
    after u seconds switch to state (ii), return to state (i) after v seconds
where u is the time a couple of cars need to clear the intersection and v is the time a few cars need to clear the intersection.

Ters

Quote from: sdog on January 03, 2016, 04:27:57 AM
Is this a brainstorming question?
I don't remember. That was ages ago!

Quote from: sdog on January 03, 2016, 04:27:57 AM
where u is the time a couple of cars need to clear the intersection and v is the time a few cars need to clear the intersection.
Unfortunately, u and v varies considerably in Simutrans, even between contemporary vehicles. For this reason, I avoid intersections with conflicting traffic flows unless traffic is very light. I don't see how traffic lights help at all. Road traffic would probably have been much easier if road vehicles had a uniform, almost instantaneous acceleration.

prissi

You can blame me for that. Before 84.20.2 they all accelerated by 16 internal units per step ...

Such a traffic light must have a maximum wait setting. Then it can be useful. Because convois stuck due to traffic check for a free road in longer and long intervalls to not overload the maps in case of a big congestions. That has the downside that convois could wait for ages under bad circumstances.