I love this site for routes. I got some great ones during a recent trip to portugal. However, one day the engine routed me along a gravel road that then turned into a logging road (nearly impassible except by fully suspended mountain bike) which then turned into what can be best described as a very difficult hiking trail, impassible by any wheeled vehicle except perhaps the most expert downhill mountain biker. There was about a mile of 20%-ish grade, very loose rock and ruts, difficult to walk, let alone walk the bike down (my only choice at that point.)
Clearly this is the result of innaccurate labeling in openstreetmap (it was marked the entire way as a typical gravel road turning into a "landtrack" which was accurate until it was not...). I edit OSM pretty often, so I isolated those really bad sections and tagged them with IMBA difficulty ratings and changed their surfaces to try to reflect reality. However, I worry that even that won't stop the routing engine from putting another cyclist on this route, and frankly, this was a physical hazard that no one should have to face on a bike unless they are really seeking a gnarly downhill challenge. What OSM tags / conditions will eliminate a section of road from the gravel routing options? There were slightly less direct, alternate gravel roads that would have been just fine, but in this hilly terrain (also riddled with large, loose dogs you wouldn't want to encounter a second time), backtracking to get to one was not a good option -- and impossible if you'd begun that overly rocky and steep descent I'm describing.
Comments
I think mtb:scale is probably the best in this scenario. cycle.travel won’t route over anything that is 3+/4 or above. mtb:scale=3 won’t eliminate it entirely, but c.t will be very reluctant to choose it – if there’s a better option available it’ll take that.
Thanks!