They say on their webpage that cloudmade uses Contraction Hierachies. If they used the plain algorithm, then there is no such stuff as penalities and so on (of course I have no idea if they tweaked it). It wouldn't suprise me that they chose high performance routing (1ms per calculation) over high-precision routing with tons off human-made tweaking and setting to give a more natural feeling.
My personal opinion is that the algorithm should be simple and the effort should be put on the data. Other people prefer to work on medium quality data and adapt their algorithms (as perfect data is impossible to get). On Sat, Jul 17, 2010 at 12:35 AM, Apollinaris Schoell <[email protected]> wrote: > > On Fri, Jul 16, 2010 at 2:21 PM, Alan Millar <[email protected]> wrote: >> >> Hi- I'm a user, not developer, trying to clean up the data in my area to >> make it more usable for routing and directions. >> >> Several times now I have come across a situation that seems wrong, and has >> not improved by itself in the last year or two as far as I can tell. That >> is where routers want you to make a U-turn on a highway link. >> >> My most recent example is here: >> >> >> http://maps.cloudmade.com/?lat=45.418666&lng=-122.321563&zoom=16&directions=45.41881686582581,-122.32349395751953,45.4324308667588,-122.36778259277344&travel=car&styleId=1 >> > > to make it absolutely correct you will need a no-left turn restriction but > this looks like a wrong cost function for the router. It's not exactly a > U-turn just a very bad angle to turn onto the trunk in this direction. > Garmin has a very high cost for such turns because they require to slow > down dramatically and default algorithm is fastest. Here it's a clear sign > for a bad router algorithm or cloudmade has an incomplete data. I still get > wrong tiles in some zoom levels. So maybe the correct ramp is not yet seen > for routing. > > >> > > _______________________________________________ > Routing mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/routing > > _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
