I was trying to work out why I can’t do a pedestrian route along this way: Way: Bubbs Creek Trail (373165162) | OpenStreetMap using OSRM, Graphhopper, or Valhalla. No part of the way is counted as routable. Which tag is disallowing that? It’s a member of several relations for hiking routes, but I can’t see any problematic tags on those either.
(I’m not planning a hiking trip there, I’m was just playing with routing after seeing this https://x.com/amazingmap/status/2033277840872079583 )
I would guess it is sac_scale=mountain_hiking. From memory, the default profiles on osm.org don’t route along paths where sac_scale is above a certain level of difficulty. That can be overridden in some contexts, e.g. where a “hiking” profile is an option.
I didn’t realise they looked at sac_scale, but I guess that makes sense. Even as I was typing the word “pedestrian” I was thinking… finding a route over the mountain tops is not really “pedestrian” routing.
So if we’re saying it’s correctly blocking the direct pedestrian route over the mountains from Kanawyers to Independence, then I suppose this means the second best route it finds is likely missing some “mountain_hiking” sac_scale tagging!
It also means thattrail_visibility=horrible on the Kennedy Canyon trail is not considered a blocker for pedestrian routing.