Path with "mountain_hiking" creates weird snapping on foot profile

[jeabapLANG]

Hi When trying to connect two dots together OSM create a completely different path than the requested one (a much longer path than the original one).

I can't understand where this error can come from and have already tried different ways to remove it without success... I also looked and the path seems to exist in the OpenStreetMap data.

If anyone has any idea what the problem might be, I really need help! Thanks in advance ;)

[jeabapLANG]

To test this issue :

Here is the road I obtain from OSRM : https://map.project-osrm.org/?z=18&center=49.449513%2C6.355011&loc=49.448922%2C6.355993&loc=49.448702%2C6.355703&hl=en&alt=0&srv=2

Here is the road I wanted (approx due to snapping) : https://map.project-osrm.org/?z=18&center=49.448770%2C6.355800&loc=49.448908%2C6.355988&loc=49.448702%2C6.355703&hl=en&alt=0&srv=2

[nilsnolde]

best to add the URL to the way in question on https://openstreetmap.org, so we can see the tags

[jeabapLANG]

I'll do it right away ;) Thx for your holy **** fast response

[jeabapLANG]

Here is the result for OSRM (Foot) : https://www.openstreetmap.org/directions?engine=fossgis_osrm_foot&route=49.44890%2C6.35594%3B49.44865%2C6.35562#map=19/49.44892/6.35566

And here is the result for GraphHopper (Foot) : https://www.openstreetmap.org/directions?engine=graphhopper_foot&route=49.44890%2C6.35594%3B49.44865%2C6.35562#map=19/49.44879/6.35577

And really strange thing by GraphHopper it seems to work but by OSRM a big NOPE 🤔

[jeabapLANG]

As said above, what could potentially cause an error like this?

@nilsnolde 😊

[nilsnolde]

Works for me for all routing engines on foot & bicycle: https://www.openstreetmap.org/directions?engine=fossgis_valhalla_bicycle&route=49.44889%2C6.35592%3B49.44868%2C6.35546#map=19/49.44878/6.35572.

Car routing is obviously not possible there. You didn't mention which mode you want to use? I assume bike?

You need to look at the tags of the way(s), e.g. this one has explicit bike access. The only way how this would not be routable is if the router decided the highway=path is not bike-routable, but neither OSRM nor the others (rightfully) think so.

[jeabapLANG]

I was using the foot mode and when foot is selected OSRM creates an alternative path because the exact part mentioned above is not recognized as having a foot access

[nilsnolde]

Did you try the link I put there and change it to OSRM? It finds the way. If that's not what you want (though it's pretty exactly the route you were first posting), we need the URL of the way.

I did notice you're using deprecated OSRM API URLs, it's hosted at https://routing.openstreetmap.de/ since a long time. Not sure if they're just linked by redirects, still better to use those URLs (e.g. look in the network tab when using osm.org).

[jeabapLANG]

I just double-checked but I think you got it wrong/took the right route.

As I explained above (see pictures), OSRM does not completely connect the path and if the point is placed slightly higher, it creates a huge detour. GraphHopper on the other hand manages to completely connect the two points no matter where they are located and does not create any detours (ref pictures above).

[nilsnolde]

Ok, this is the way: openstreetmap.org/way/203219837. It has sac_scale=mountain_hiking and seems OSRM doesn't like that. Nothing you can do other than PRing a fix to the foot.lua.

[osmuser63783]

Seems like this is a feature, not a bug, it was discussed here: https://github.com/fossgis-routing-server/cbf-routing-profiles/issues/9

The default foot profile used by by openstreetmap.org simply avoids any paths with sac_scale=mountain_hiking or higher, and this way is tagged mountain_hiking.