Comment by c0nsumer | Hacker News Reader

Comment by c0nsumer | Hacker News Reader

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Thank you for doing this.

For years I've contributed trail data to OpenStreetMap, mostly to support mountain biking, but this is the exact kind of other project it benefits. It was really neat being able to try this on local trails and see just what happens.

One question: What tags does it give priority to?

I ask because I tried it on a local trail system, and it seemed to prefer the wide paved and dirt path as opposed to the mountain bike trail. It was weird in that sometimes it'd use the single track, but in others it'd do sort of an awkward thing through the parking lot / service road (highway=service, service=parking_aisle) then use some of the single track (eg markers 1-2) before jumping on the paved path and pretty much ignoring the single track. The single track is really popular with trail runners in this park, so it got me wondering.

An example of that is here:

https://trailrouter.com/#wps=42.65195,-83.05484%7C42.65088,-...

Thanks for all your contributions to OSM! If you ignore all of the greenery preference then it gives priority to tags:

foot=designated route=root, hiking highway=footway, path, track, bridleway, pedestrian, living_street, residential, service, unclassified maxspeed < 20km/h

Looking at your area (https://www.openstreetmap.org/way/191828180#map=15/42.6423/-...), all of the trails are given equal preference. As a result, it then falls back to whichever gives the shortest path. It's choosing the asphalt one (linked above) just because it's the shortest path. In the future, I may add a surface preference option - so you could give additional preference to non-paved paths.

Thank you very much for explaining that. That makes a lot of sense. I really wish there was a better way for tagging things like narrow/twisty natural surface trails vs. wide flat ones, but that seems all balled up in US vs. EU hiking things, MTB tagging... It's a mess.

(Making it worse, someone naively editing a mountain bike trail in iD will end up inadvertently flagging it as highway=cycleway. And then people using OSM for cycling directions get routed down an MTB trail... Yay.)

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