Hi, Am Mittwoch, 11. April 2012, 15:42:29 schrieb fly: > I still do not get one major point which was totally left out on the first > scheme. What actually belongs to a "point" and how are they tagged. Especially > on big crossings and roundabouts I always was confused (e.g. it might be > possible that a part of this point is blocked but how do I know which one and > you might be able to use the first/last exit/entrance of a junction but not the > rest. )
Indeed, this is what I was worried about as well. Here's a proposed (partial) fix, which starts from the original proposal. Let's assume that 123, 456 and 789 are connected LCD which describe a road. Further assume that at 456 there's a big intersection. Then: - All ways between 123 and 456 are marked tmc=DE:123+456, and all ways between 456 and 789 are marked tmc=DE:456+789. - All ways on the intersection 456 leading from 123 to 789 are then marked tmc=DE:456+. This has several advantages: - A traffic jam between 123 and 456 will not block the intersection 456 anymore. - Exits are defined as follows: an exit at 456 in positive direction starts at a way that is tagged either tmc=DE:456+ or tmc=DE:123+456 ("from"), uses a node that is part of a way tagged either tmc=DE:456+ or tmc=DE:456+789 ("via") and ends at a way that is tagged neither tmc=DE:456+ nor tmc=DE:456+789, nor tmc=DE:123+456 ("to"). An exit is therefore a maneuver. This may sound a bit technical at first, but none of this is exposed to the tagging, and the idea of an exit is probably quite intuitive. - Likewise, entries are defined. - Automatic consistency checking is still possible, as there are no holes. There is at least one issue that still has to be addressed: this tagging does not imply an ordering of the exits / entries; it is not clear what the first, second… exit would be. Eckhart Wörner _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging