Martin, On Tue, Mar 22, 2011 at 6:32 AM, M∡rtin Koppenhoefer <dieterdre...@gmail.com> wrote: > 2011/3/21 David Paleino <da...@debian.org>: >> On Mon, 21 Mar 2011 21:12:55 +0100, M∡rtin Koppenhoefer wrote: >>> 2011/3/21 David Paleino <da...@debian.org>: >>> To not be misunderstood: I prefer explicit sidewalks (=separate ways) >>> as I wrote above. But you should not map them as if they were >>> independent ways. >> >> They aren't: have you checked my proposal? They're part of the same relation >> (street, or associatedStreet). > > > If you need a relation for every sidewalk, it is clear that you are > redefining footway, because not interpreting this relation will lead > to misunderstanding for all footways (they would be understood as > independent ways and routing would work worse then with no sidewalk > mapped at all).
Adding footway=sidewalk is not redefining highway=footway, just like saying service=parking_aisle is not redefining highway=service, rather it is a refinement. Likewise, using relations are not redefining highway=footway; relations (to associate sidewalks with an adjacent road) are not required, but rather add information that routers can exploit to give more detailed directions. Both methods have advantages and disadvantages. If one wants both to associate a sidewalk with a road, AND to be specific about crossings, barriers, surface materials, width, etc, then it will get complicated no matter which method you prefer. With one you have two adjacent ways, but require a relation to associate them. With the other you might have to break the road into many arbitrary separate ways to account for changes in the sidewalk. Both methods require tools to enable clear and efficient mapping. And to be clear, I personally prefer mapping as separate ways, which works especially well for my area in the suburbs, but I'm not so concerned about creating relations right now. I can imagine it wouldn't be difficult to write a tool which would generate candidate sidewalk+road pairs based upon the geometry, which upon verification would automatically create or modify relations associating them. -Josh _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
