As one of the developers of the GraphHopper routing engine, I would like to learn what improvements should be made from the point of view of the OSM community. Regarding the routes suggested by GraphHopper on openstreetmap.org or graphhopper.com/maps (no matter which vehicle profiles). I am especially interested in error patterns that happen frequently and in dangerous route suggestions.
There was a lengthy discussion on IRC today about penalties for border-crossings (particularly with respect to avoiding Kalingrad Oblast for travel to Lithuania & Latvia). This may have particular relevance for the UK now. Border facilities are, however, poorly mapped on OSM, and I’m not aware of suitable tags to indicate the length of formalities (e.g., Argentina/Chile crossings on Tierra del Fuego may take an hour: at least on a bus all bags are x-rayed), which likely differ between private & goods vehicles.