On Sun, Sep 20, 2009 at 1:43 AM, Martin Koppenhoefer <dieterdre...@gmail.com> wrote: > > yes, but that's not the problem: straight parallel ways. The problem > arises when they change (become one more or less), on intersections, > etc. Try to imagine a situation like the one I posted above in a > geometrically reduced system: it will get way too confusing. If we map > lanes where they are, there is another benefit: positional correctness > and ease of topological structure: you see what you do.
There seems to me to be good arguments for both of the suggestions being discussed. For clarity, here is a summary of the two main options: 1) modeling a *lane* as a series of nodes (as suggested by Martin) 2) modeling a *set of parallel lanes* as a series of nodes (as suggested by John) In 1), tags referring to the lane are applied to the way that explicitly represents the lane. Lanes of the same street are grouped with a relation. In 2), tags referring to the lane are (somehow) applied to the way that explicitly represents the entire street (group of parallel lanes). I would like to think that a structural database change is not necessary to implement 2). All that would be required is a way to denote which tags refer to which individual lanes (e.g. lane:*=*). I know, John, that you prefer a change to database structure instead. Note first, however, that regardless of whether lane:*=* or a new database table is used, editors could be changed to allow for the kind of editing you describe (http://wiki.openstreetmap.org/images/4/46/Lane_group_example1_screen_2.png). It's still 2). Personally, I think both 1) and 2) could be used, as applicable. Specifically, 1) where lanes are not parallel, and 2) otherwise. I prefer 1), though, as it is more extensible (e.g. to use of further relations indicating ability to change lanes - with 2), it's likely to get messy). I also don't agree with John that 1) is an "abuse" of relations. _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
