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.
I followed the instructions from
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