geometry collision on junction between stranded left-turners and cross traffic

eclipse-sumo / sumo

Eclipse SUMO is an open source, highly portable, microscopic and continuous traffic simulation package designed to handle large networks. It allows for intermodal simulation including pedestrians and comes with a large set of tools for scenario creation.

https://eclipse.dev/sumo

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geometry collision on junction between stranded left-turners and cross traffic #9041

Open MohamadReza-Haghani opened 3 years ago

MohamadReza-Haghani commented 3 years ago

Hi,

I made a simple four-way signalized intersection in SUMO. When I run it, I see that left-turning vehicles have conflicts with straight moving vehicles from the opposite direction. In this situation, left-turning vehicles come into the intersection and cross the other vehicles instead of waiting for the straight moving vehicles to pass. How can I change their behavior so they do not cross each other.

Thanks, Reza.

namdre commented 3 years ago

if you define the signal plan yourself, make sure that the left-turning stream gets state "m" (minor green) which shows as a darker shade of green compared to "M" (major green).
version 1.10 fixed a bug where left-turning vehicles could sometimes enter too early (which version did you use?)

MohamadReza-Haghani commented 3 years ago

Thanks dear Jakob. I found that my problem was that the signal did not have all red time. Therefore, vehicles of the next phase crossed over the vehicles that got stuck in the intersection from the previous phase. I added all red time. So the intersection becomes clear before the next phase green time, and vehicles do not cross each other any more.

namdre commented 3 years ago

Actually, vehicles should still respect each other even when there is no all-red time. Feel free to attach a sample scenario as this may reveal some problem with the network model or the simulation behavior (and I will then re-open this issue).

MohamadReza-Haghani commented 3 years ago

ezyzip.zip

If you look at these files, you see that, without all red time, the vehicles stuck from the last phase cross other vehicles and exit the intersection.

namdre commented 3 years ago

Thanks. The model is working mostly as expected:

the cross traffic on the rightmost lane correctly waits for the "stranded" left turners
the cross traffic on the middle lane ignores them because the center line of it's lane does not intersect the center line of the lane where the left-turners are waiting (their connection is split in two internal lanes by the waiting position on the junction).

If the left-turn geometry is altered to shift the waiting position a bit further ahead into the junction it works nicely. Nevertheless, it's still a bug since the conflict check should take lane widths/ vehicle widths into account rather than rely on the center line.