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Problem with routing


#1

Hello,
firstly please move topic on correct place, if this isn’t it.

Issue reported by one user of Directions API over Locus Map app. Routing returns no result in case
https://graphhopper.com/maps/?point=36.779743%2C28.248805&point=36.795155%2C28.232441&locale=en-US&vehicle=foot&weighting=fastest&elevation=true&use_miles=false&layer=Omniscale

, but returns valid result, if initial point moves only a tiny distance to next path, check: https://graphhopper.com/maps/?point=36.779743%2C28.248805&point=36.795123%2C28.232476&locale=en-US&vehicle=foot&weighting=fastest&elevation=true&use_miles=false&layer=Omniscale

Check OSM: https://www.openstreetmap.org/edit#map=19/36.79501/28.23294

I’m not GraphHopper or OSM expect, I just look on this from users point of view. Thanks for looking on it!
Menion


#2

The problem seems to be this path: http://www.openstreetmap.org/way/492814037 which is completely disconnected to the rest network. Only local people know if it should be connected or completely removed (looks duplicated to the other path IMO)


#3

Hello Peter,
understand, thanks for answer. I was also looking on this path and it looks like simple record with device, uploaded and commited without any modifications.

Anyway I expect, there will be a lot of similar tracks in the world.

Here we have one, correctly defined and usable path for a routing, just a few meters next to this one. So as an amateur, I expect that routing engine use some closest possible path to achieve my goal, is this incorrect expectation?


#4

Ah, you are right. There is a method called “small subnetwork removal” that we normally apply in those cases. Will have a look why this is not done in this case.


#5

Oh, this was a hard one. I think I have now understood this case: there are two overlapping&identical ways:


Forming together a network of several hundred nodes (together with http://www.openstreetmap.org/way/492814053)

So this should not occur in other parts of the worlds and if you remove those three ways this should be fixed.


#6

Good day Peter,
thank you for your invested time. Hope you are right and that same problem does not occur on other places as well.
I’ll forward your information to guy, who live there and who reported me this problem so he may fix it correctly. Thanks!