Hi Martin, I surely get the intention of enabeling renderers of any kind to draw more precice representations of lanes on a way. But I have two comments for you:
1. I think it PARTLY IS about position. Your tag does two things: allowing the renderers to position the lanes correctly in reference to the way and it allows the renderes to know which lanes continue and which start/end if the lanes count changes. You may be only interested in the second part, but the first part is still a valid use of it. 2. I have problems with the tag because it is (to my knowledge) the first 'meta-tag' to be actively used by consumers. It doesn't describe a feature of the real world but how a feature is described by our tagging. I much rather would like to see this information embedded in the existing tags like e.g. the lanes=* tag itself or by one of the various lane connection schemes. This would also fullfil the second use-case mentioned above. Imho introducing a tag that says how other tags work will make it more complicated for for data contributors, especially if this is introduces to other schemes where more than one possibility of tagging exists (public transportation, house numbers, etc.). It also has the chance of getting out of sync if some one changes the original tag (or in your case the relative position of the way) but doesn't change the meta-tag accordingly. (Actually, I'm in favor of drawing the lanes seperately and even using areas, putting them into a relation to form the actual highway and letting the editors handle them just as one way in every but the closest zoom level. But I know that this is opposed to by the majority, so I'm mentioning this very very quietly.) Best regards, Chaos 2012/12/21 Martin Vonwald <imagic....@gmail.com>: > 2012/12/20 Pieren <pier...@gmail.com>: >> I guess it's purely for rendering. Why not (like 'label'). But it's >> only useful if you render lanes which is something I've not seen so >> far (for nano mapping ?). > > Think of a navigation system with lane assistance - it's just a > renderer with a very high zoom level. ;-) > > >> The point about car navigation systems is >> incorrect. It does not care about the highway way position (and no GPS >> device is accurate enough to determine on which lane you are). > > You got me wrong: the exact position is irrelevant. This tagging is > about the position and course of the lanes within(!) the outline of > the road. The navigation system should present you with a > representation of the road ahead that is as realistic as possible. > Especially the course of the lanes is very important, because drivers > strongly rely on the geometry of the road: they should recognize it in > the lane assistance. It's all about representation! > > I most certainly have to create an example (for consumers) which shows > how to estimate the course of the lanes. > > Thanks for your feedback. > Martin > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > http://lists.openstreetmap.org/listinfo/tagging _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging