On Wed, Mar 19, 2008 at 6:02 PM, <[EMAIL PROTECTED]> wrote: > I played a little last night thinking of how a router application might > sense junctions and worked out a solution at the way/map level. > > see: > http://www.openstreetmap.com/?lat=51.11773&lon=-114.0701&zoom=17&layers=0BFT > (osmarender has rendered this, but you have to go to edit to see what I did). > > Basically there aren't direct connections between crossing streets, > instead there are very short 1-way connectors which are positioned so that > they are the first junction you come to. Hence any router application > would say 'turn left' thinking that it was the first junction.
I've had a look, and what you've done is pretty creative! But I don't think it's a particularly good idea. I expect the burden to be on the routing software to detect that it's a dual carriageway and handle the turns appropriately. There's no way that all the junctions are going to be tagged with such fictional roads as you've done with this one, so the software would have to handle similar junctions that are tagged in a more straightforward fashion. And if it can handle them, then there's no need for what I'm going to call "Basket Weaving" :-) > I think that if this would still be better solved in some 'relationship' > way as constructing every junction like this would be a pain, and I'm sure > that it would break in some situations. I think the situation could be helped by relations, but again not every junction will have them, so the software will have to handle it without. It'll not be terribly hard to post-process the OSM data to autodetect dual carriageways and give the option of saying "turn left" instead of "take the second left" when turning onto one. Cheers, Andy > Cheers, > Mungewell. > > > > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk > _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
