[OSM-dev] detecting street made up of multiple lanes

marcus.wolschon at googlemail.com marcus.wolschon at googlemail.com
Tue Mar 17 11:55:00 GMT 2009


Hello,

I am currently presented with a quite puzzling problem.
For low zoom levels Traveling Salesman (or more exact, the LODDataSet)
merges streets that are broken up into multiple ways
into as few ways as possible and then simplifies these polylines.

Now there are road-constellations (first detected in Helsinki, Finnland
Bug-ticket: http://travelingsales.sourceforge.net/bugs/view.php?id=52)
where roads start as 2 parallel ways with oneway=true, then merge into
a single way and then split up into 2 parallel ways with oneway=true again.
One example would be "name=Pakilantue" near the crossing with "name=Kehä
I".
Another example would be pretty much any german motorway.

I would like to detect such ways and merge the 2 parallel ways into a
single one.
My question:
Given only the 2 parallel ways and their nodes, how could I detect these
to be 2 lanes of the same street?

I know/I can assume:
* they have the same namd and/or ref
* both are oneway=true

I can not assume:
* that both ways meet at a common point like in Helsinki


Marcus




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