Hi Oskar, I think the mapping of the roundabout is part of the problem. It's diameter is a bit too small and therefore the connection of the way https://www.openstreetmap.org/way/78515591 is not on the roundabout but on https://www.openstreetmap.org/way/78515465 I think the roundabout should be enlarged and way 78515591 should be connected to it. I also wonder why this short part of the road doesn't have the name=Kalda tag. The router Valhalla is rather new, maybe you should report the issue to its developers. Anyhow, I don't see the wrong results with a small Garmin map compiled for that area (tested with MapSource and Basecamp), also not with your map loaded into Basecamp. I get the expected route similar to that from Graphhopper. You may want to add --link-pois-to-ways to your options, but that is not important here. Maybe you have a special configuration on your device? ciao, Gerd P.S. Karl modifed the OSM data while I was writing my reply, so some comments may no longer make sense, but I hope you get the idea. ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Oskar Ohakas <oskar.ohakas@proton.me> Gesendet: Donnerstag, 30. Mai 2024 06:52 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: [mkgmap-dev] Wrong route on roundabout Hello, I compiled my first gmapsupp.img and on test drive garmin offered an obviously wrong route on a roundabout (garmin.jpg). On OpenStreetMap i get the same wrong route with algorithm Car (Valhalla), but Bicycle (Valhalla) and other routing algorithms will give the correct route. https://www.openstreetmap.org/directions?engine=fossgis_valhalla_car&route=5... I followed the instructions from https://wiki.openstreetmap.org/wiki/Mkgmap/help/How_to_create_a_map mkgmap \ --route \ --add-pois-to-areas \ --bounds=bounds \ --index \ --gmapsupp \ 6324*.osm.pbf Have I missed an important option? Is it possible to fix the problem in compilation phase or is it something confusing for Garmin algorithm in OpenStreetMap data? If it helps, then I have uploaded the gmapsupp.img for possible inspection to the address https://0x0.st/XNpC.img/gmapsupp.img Any helpful insights are welcome. Oskar Ohakas