No route found between points for very small distances.

[DamirTomic]

Issue

I'm getting no route found between points error when doing some very small GPS distances, for example distance between 2 stores that are located in the same building (it's a mall):

for example, when running OSRM backend locally:
http://localhost:5000/route/v1/driving/23.3535,42.62397;23.35345,42.62357

I though that maybe switching to walking would help, but it did not:
http://localhost:5000/route/v1/walking/23.3535,42.62397;23.35345,42.62357
I still get "no route found between points" error.

It seems that nominatim marks these 2 locations as the same address (which technically is true since both stores are in the same, large building).

https://www.openstreetmap.org/directions?engine=fossgis_osrm_car&route=42.62397%2C23.3535%3B42.62357%2C23.35345
Both GPS coordinates get translated to "Sofia Ring Mall, 214, Ring Road, zh.k. Moreni klub, kv. Simeonovo, Sofia, Vitosha, Sofia City, Sofia-City, 1434, Bulgaria"

I would expect OSRM to return a very small distance such as 50 meters and 10 seconds. Currently, when this happens, I manually calculate geodesic (air) distance.

This happens both locally and on openstreetmap.org, so it's not a map issue or anything like that.

[DennisOSRM]

Origin and destination are within a mall with no paths mapped in the area. One could argue that OSRM's answer isn't incorrect according to the data, and arguably better than snapping to nearby roads.

[DamirTomic]

I agree that snapping to nearby roads is less correct than this, but maybe a new feature is needed? Like, adding a dotted line between 2 points if they are under a certain distance? Or, if I use a flag: fallback_geodesic=true, then you calculate the geodesic (air) distance between the destinations?

Google maps do something like this:

[DennisOSRM]

Indeed. This is an exciting feature that is currently being worked on: #7161