[GraphHopper] Graphhopper sending back "not found"

[Pascal DANEK]

Hi Peter,

We played with the settings (minNetworkSize and highResolution) and it solved a certain class of problems. However, most of the requests still fail. After deeper investigation, we discovered it is due to one of the two points using a way which is a oneway, leading to a subnetwork from which you can’t return. It occurs in many airports or within private areas.

I think it is a bug in data, but despite of this, I believe Graphhopper should manage that properly in order to make it really useable. (osrm has the same issue). I mean, we have thousands of requests which fail.

What we did for now: We implemented in the web service an option specifying that the service, in case of a “not found”, move start or destination point (alternatively) within a certain distance, until it finds a route. This actually solve the problem by making the routing service using a routable way. Are you interested by this patch ?

Of course, it is only a workaround, maybe not suitable for a long term solution. We think that a correct way to fix this would be to clean the graph, at the prepare stage, removing nodes after a one way if they are less than N. What do you think about this ?

—pascal

Le 2 juin 2014 à 10:48, Peter K <peathal at yahoo.de> a écrit :

> Hey Pascal,
> 
> there are cases with oneway where it wouldn't be logical to return a route. Still there are workarounds like described here:
> https://lists.openstreetmap.org/pipermail/graphhopper/2014-May/000960.html
> 
> But in your case it is a mapping problem with the incorrect oneway somewhere here:
> http://graphhopper.com/maps/?point=43.697867%2C7.121721&point=43.69784%2C7.121657
> 
> which makes the whole district in the south unavailable.
> 
> Regards,
> Peter.
> 
> 
>> Hello folks,
>> 
>> I am Pascal and  I currently evaluate Graphhopper as an alternative routing service for my company.
>> 
>> We are currently facing an issue with an itinerary: from “Nice" to “St Paul de vence”, we just get a “not found” response from GH.
>> 
>> I tested the official online instance and I get the same behaviour:
>> http://graphhopper.com/maps/?point=nice%20&point=saint%20paul%20de%20vence
>>  
>> Whereas the opposite works fine:
>> http://graphhopper.com/maps/?point=saint%20paul%20de%20vence&point=nice
>> 
>> Is it a bug related to some kind of one way direction ?
>> 
>> Should I submit a bug, or do I miss something ?
>> 
>> Thanks in advance for your help,
>> 
>> —pascal
> 
> _______________________________________________
> GraphHopper mailing list
> GraphHopper at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/graphhopper

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/graphhopper/attachments/20140616/855715d5/attachment.html>