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graphhopper / graphhopper

Open source routing engine for OpenStreetMap. Use it as Java library or standalone web server.

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U-Turn at motorway<->motorway_link connection if the motorway is oneway=no

sd5 opened this issue · comments

commented

Describe the bug
See one of the screenshots below.
At the connection of the highway=motorway to the highway=motorway_link (at node/295800986) GraphHopper thinks it can do a U-turn. The motorway is tagged with oneway=no at this location due to construction work.
I'm not sure if this is intentional behaviour, but all other routers I tried do not make a U-turn here but instead continue to route into the next village and make the turn there.
The problem was first discovered by OSM-user "furgas" in Changeset 139458779.

To Reproduce
Use one of these links:
GraphHopper on openstreetmap.org
GraphHopper on graphhopper.com

Note:
Yesterday (07. August 2023) I have created a turn-restriction to prevent this behaviour: relation/16167144
So as soon as routing data is updated, this bug might not be happening anymore at this particular location.

Expected behavior
No U-turn at this location, even without a turn-restriction-relation.

Screenshots & Logs
grafik
grafik

commented

Thanks for reporting this. We probably need to take into account the road class to prevent such u-turns. Increasing the u-turn costs would probably also yield another route.