[mkgmap-dev] Routing issue at staring oneway road

Fri Apr 8 12:40:49 BST 2011

>> @Markus:
>> Are there any signs, that the destination road is a oneway?
>
> The destination i want to get routed to is about at the point
> http://www.openstreetmap.org/browse/node/1079735170
>
> So it is not a oneway.
>
> I was just right now by foot out at the place with the Garmin Dakota 
> to reproduce it in a better way. The results are a bit strange. When 
> iam at Neugasse and let it calc the way to the destination, when i can 
> not reproduce the bad routing up the Kreuzstraße -> Rudolfstraße -> 
> Rosenstraße.
>
> The bad routing happens when iam coming from more far out. The 
> original route was over Rudolfstraße -> Rosenstraße. But when i drive 
> down the Neugasse i get a rerouting and that is heading over 
> Kreuzstraße -> Rudolfstraße -> Rosenstraße.
>
> So its looking now more like someing from the Dakota routing recalc 
> and not so much from the mapgeneration itself. Is there any knowlege 
> how a new calculated routing is different from a updating recalc of a 
> route on that Garmin devices? Maybe the access=destination tag at that 
> part of the city could be part of that routing troubles too ...
>
>
I asume it a effect of the routing algorithm of the dakota. Your 
destination lies an a street with access=destination. If you come from 
far out, you are not in this area and have to enter a street with 
access=destination. If you start in Neugasse, you are already inside the 
destination area. So your routing has not to enter a destination area 
again and its okay to go through Kreuzstraße. Something like this...