Routes create U-turns instead of using roundabouts/viaducts

konstantinburcev · September 17, 2025, 9:09am

Hello,

I’m having problems with ORS routing where it creates U-turns instead of using roundabouts or viaducts.

This happens with the forestry truck profile.
Example attached: instead of going through the roundabout, the route makes a U-turn maneuver, which doesn’t make sense in practice.

I’ve tried adjusting the request (e.g. shortest/fastest, different vehicle types), but the result is the same. I also tried adding avoid_features: ["ferries"] in case it could disable CH, but it didn’t help.

Questions:

Why does ORS prefer U-turns over roundabouts in cases like this?
Could this be due to OpenStreetMap tagging issues (e.g. missing hgv=yes or general access tags)?
Are there recommended ways to fix or work around this (custom model, penalties, configuration tweaks, or something else)?

Ultimately I would like the routes to always use the roundabout/viaduct instead of generating U-turn instructions.

Thanks in advance!

But also with the driving-car profile

jschnell · September 17, 2025, 9:12am

Hey,

would you mind sharing links or cURL-commands for the examples you gave?
They are super hard to reconstruct otherwise.

Thanks a lot

konstantinburcev · September 17, 2025, 9:21am

example from ORS demo website:
1)

driving-car example:

andrzej · September 22, 2025, 9:27am

Thanks for providing links to the example routes!

I’ve had a look at the underlying OSM data and apparently the issue are missing turn restrictions. In the presented scenarios one would normally expect relations preventing the u-turns, like this.