Maarten Deen wrote: >John Smith wrote: >> On 11 July 2010 06:43, Chris Dombroski <cdombroski+osm at icanttype.org> >> wrote: >>> I ask because I think this is the cause of stupid GPS directions at times >>> "make a left, followed by a slight right" >> >> Isn't that a problem with the routing software, not the data? > >Not IMHO. > >If you have a layout like this (use a fixed-width font): > > | | >A----+-+ > | +----B >C----+-+ > | | > >And you want to go from B to A, why would routing software say "go straight on" >and not "go right, then go left"? > >And option is to map it like this: > | | >A----+ | > |\| > | +----B > |/| >C----+ | > | |
I use either this or a slight modification where ways A and C meet on the left side and B continues across the right side. Usually I decide based on whether A/C or B is a more major road, and thus what classification the pieces in the middle should be. In some US counties, the imported TIGER data treats an intersection of divided highways as a single node: http://www.openstreetmap.org/?lat=39.785241&lon=-75.546328&zoom=18&layers=B000FTF This is IMO a horrible solution, especially when channelied left turns are added between the main lanes. I changed a nearby stretch of US 13 to keep the main lanes straight, and it looks much better: http://www.openstreetmap.org/?lat=39.70937&lon=-75.56229&zoom=17&layers=B000FTF _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
