I don't agree about data clutter ever being a problem. Mis-tagged data can be a problem.
Separate sidewalk data is useful for wheelchair/accessibility routing, for marking steps on the sidewalk on a steep road, for marking the intersections with driveways, for marking ramps and crosswalks, for showing the spatial relationship between sidewalks and obstacles (power poles, fire hydrants, bicycle racks, benches, bus stops shelters, etc.). I think that tying two dimensional data to a one dimensional roadway will mean that we will eventually have to come back to add the data as OSM gets more data-dense. OSM has long since become more than just a map about roads and already includes boat navigation information, runway information, trails, buildings, radio towers, etc.; adding sidewalks won't hurt but should help. I'm for the idea of mapping sidewalks separately in all cases, tying them to their roadways with relations, and including as much data as possible about ramps, obstacles, crosswalks, and driveway intersections. Sidewalks should only connect to a roadway where there is a crosswalk and should otherwise be connected by driveways and such. Bill R. WASHBURN On May 8, 2014 6:14 AM, "Martin Koppenhoefer" <[email protected]> wrote: > > 2014-05-08 11:58 GMT+02:00 Serge Wroclawski <[email protected]>: > >> Being an American has nothing to do with a really bad data design. >> I've been an American 35 years and I think this is really not a good >> way to model sidewalks. >> > > > +1, agree, my main concern is that as pedestrian you can actually cross a > road at any point if it is not too much traffic and there are no other > rules forbidding it. Generally with explicity footways routing gets worse > in my experience because there mostly only few connections from the > sidewalk to the road mapped. > There is no way to distinguish separate footways (e.g. separated by a > guard rail) from those separated only by a curb. If mapping explicit > sidewalks there should also be some entity that ties all road lanes (and > sidewalks) together to one object. > > On the pro side you can add surface, width and other information to where > they apply, while with tags on the main centre highway way you would have > to split the whole road for every change on the sidewalk (or any other of > its lanes). > > > > >> >> The problem (aside from the issue of data clutter) is that the >> sidewalk data can't be used for pedestrian routing because the >> information about the street is not captured. You can't tell someone >> to follow Main Street, because the path is not labeled as such. >> > > > well, you should either use a relation to tie them toghether, or add the > common attributes like name etc. to all elements (i.e. also to the > sidewalk). > > In the end this is a question of detail, for very detailed mapping there > is a benefit IMHO in mapping sidewalks on dedicated objects, but I'd see > this more like explicit lane mapping, i.e. better use another tag than > highway for this in order to avoid confusion with indipendent footways. > > cheers, > Martin > > > > > _______________________________________________ > Talk-us mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/talk-us > >
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