On Thursday 21 May 2009 00:30:13 Radomir Cernoch wrote: > However it's important to notice that two polygons can never overlap > (unless there is a futuristic city with zone-30 area flying in the air > above a 130 km/h highway). > > > Now we have an urban area, with a circular road with maxspeed=50, and > > streets and cul-de-sacs left and right of that road with maxspeed=30 > > zones. And that is just a simple example. The polygons are going to be > > complex in some cases. > > > > > I can imagine a situation, where a normal 50 km/h road goes through the > > > middle of a zone-30. Then there are two options: > > > 1) You split the zone-30 polygon into 2 polygons. > > > 2) You tag the 50 km/h road with "maxspeed=50". > > > > Right, exactly the scenario I mentioned at the top of this msg. > > I agree that the polygons are going to be complex. As complex as current > 'landuse=residental' polygons or administrative border polygons or... > I know it's pain to work with them, but the solution is to learn JOSM to > split map into layers, not to adjust the data-model.
You are still missing the point! The road network is a 3D network. Your 2D polygons can't model the fact that traffic zones are not 2D, but chunks of that 3D network. It is completely possible for a village ringroad on a bridge (highway=primary or secondary) to have a maxspeed of 80 km/h due to being outside the build-up zone, not because there is a sign on it that says 80 km/h. It is also possible at the same time for the road under that bridge to have a maxspeed of 50 km/h due to being inside the build-up zone. The point of the bridge has one lat/lon, but the roads are vertically separated. This will never fit in any 2D model. -- m.v.g., Cartinus _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
