From a data consumer point of view, what type of tagging would be reasonable to indicate the, for lack of a better work, direction of travel a stop, give way or traffic light has effect?
> On Mar 17, 2017, at 3:54 AM, Daniel Hofmann <hofm...@mapbox.com> wrote: > > Jumping in here to give a perspective from a routing engine (OSRM, > https://github.com/Project-OSRM/osrm-backend#open-source-routing-machine > <https://github.com/Project-OSRM/osrm-backend#open-source-routing-machine>). > We do not handle direction tags on nodes which indicate a property for a way > or a turn at an intersection. The example with stop signs and give yield > signs is spot on. Even worse is the assumption that routing engines can just > infer the direction by checking the distance to the nearest intersection. > This is in conflict with how parsing and creating a graph works. > > There is a similar problem with exit_to node tags, indicating the exit way > destination - you can read about it here > > - https://www.openstreetmap.org/user/daniel-j-h/diary/40555 > <https://www.openstreetmap.org/user/daniel-j-h/diary/40555> (en) > - https://www.openstreetmap.org/user/daniel-j-h/diary/40554 > <https://www.openstreetmap.org/user/daniel-j-h/diary/40554> (de) > > Cheers, > Daniel J H > > > On Fri, Mar 17, 2017 at 11:25 AM, Martin Koppenhoefer <dieterdre...@gmail.com > <mailto:dieterdre...@gmail.com>> wrote: > > 2017-03-16 5:13 GMT+01:00 Tod Fitch <t...@fitchdesign.com > <mailto:t...@fitchdesign.com>>: > The “direction” tag [1] has different uses that seem disjoint to me. > To specify the orientation (compass point or degrees from north) of an object > (adit or cave entrance, etc.). > > "orientation" would have been a better descriptor IMHO, but the crowd uses > this tag differently (see taginfo, also subtags like roof:orientation, ...). > Direction is working for me nonetheless. > > > 2. To specify direction (clockwise/counterclockwise) around a roundabout (not > sure why this is needed as it should be apparent from local laws or specified > with a “oneway=yes”). > > > agree with you > > > 3. To indicate the direction (forward/backward) a stop or yield (give way) > sign has effect along a way. > > > broken. From time to time people are coming up with features to tag on nodes > that require (or seem to require) the information of a direction. Taking the > direction of a different object (e.g. here a way) doesn't seem a healthy way > to represent this. Ways might get split, might get reversed, nodes might be > (or become) part of several ways, etc. Either use a cardinal direction or a > short way stub or a relation, etc., but not "forward" or "backward" tag > values on a node, it simply doesn't make sense. Tags should refer to the > object they are tagged on. > > > > Oddly, that third use seems only for stop and yield signs but not for traffic > signals where a “traffic_signals:direction=forward | backward” tag is to be > used. However that seems to be the most used form [2]. Apparently some have > figured that if we have “traffic_signals:direction” there should be > “stop:direction” [3] and “give_way:direction” [4] tags. > > > similarly broken > > > I would keep the variant 1 and discourage 2 and 3. > > Cheers, > Martin > > > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org <mailto:Tagging@openstreetmap.org> > https://lists.openstreetmap.org/listinfo/tagging > <https://lists.openstreetmap.org/listinfo/tagging> > > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging
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