[OSM-talk] Lightning fast car routing built on OpenStreetMap data, with draggable routes

Kai Krueger kakrueger at gmail.com
Sun Mar 18 06:58:46 GMT 2012


Lester Caine wrote
> 
> I must say I'm seeing the same strange effects on routing in the UK.
> Although 
> mapquest is a little slower, it does at least pick up the faster roads
> rather 
> than routes that are perhaps 0.5km shorter but using roads with many
> roundabouts 
> rather than the adjacent motorways or dual carriageways with none.
> 
Despite using the same data, the various routers based on OpenStreetMap do
sometimes seem to generate rather different routes. Either, because they
assume different default speed profiles for various OSM highway classes,
because they add different heuristic penalties (such as for traffic lights
or corners), or because they implement different sub sets of OSM taggings. 

Comparing the various routers and where they differ will hopefully help
improve those defaults, as well as identify areas, where the data needs to
be enriched so that the routers have an easier job on selecting the best
route.

In case people are interested, to make this comparison easier
http://apmon.dev.openstreetmap.org/routing/ allows you in a single interface
to select which of the 4 main OSM routing engines one wants to use (OSRM,
MapQuest Open, CloudMade and Gosmore) and allows to quickly switch between
them to compare. One should remember, however, that they all use data
extracts from different times. While OSRM and MapQuest should be pretty up
to date, I am not sure how often CloudMade or Gosmore update.

Unfortunately, given that the dev server, through which the results get
proxied, can be rather slow, one can't really appreciate the wonderful speed
of OSRM.

Kai

P.S. It is really great to see all those improvements flowing into OSRM! It
will hopefully help make OSM data ever more routable. Thanks and
congratulations to Dennis and everyone else who might have been involved!



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