Hi, I'm in the process of adding more detail to the major junctions in terms of lane counts, turn lanes, width, etc.
There seem to be two tagging schemes in parallel: - the turn:lanes[1] scheme which adds lane descriptions as tags to way segments. - the turnlanes:turn[2] scheme which adds lane connections via relations to the junction nodes They don't mach exactly in the kind of information the record. The turn:lanes scheme describes the lanes and lane markings leading to the junction (with only fuzzy information on where the lanes lead). The turnlanes:turn relation then describes how each lane is connected to an outgoing direction (without stating how they are marked). But they also encode the same information in two ways, for example the length of the turn lanes (by way segment length with turn:lanes, as numerical tag value with turnlanes:turn). Both are nicely supported by a JOSM style (turn"lanes) [3] and a JOSM plugin (turnlanes:turn). According to taginfo, turn:lanes is used approx. 47k times, turnlanes:turn is used approx. 10k times. I personally don't like the turnlanes:turn scheme very much because it introduces quite a lot of extra relations per junction which probably make it less maintainable then tag-based schemes or a single-relation-per-junction scheme, but that is more a question of taste than anything. This topic was briefly discussed already on the German and Austrian talk-lists with mostly the opinion to use the newer and more elegant turn:lanes scheme. But I see no easy way of enhancing the turn:lanes scheme to include the missing connection information without bloating it up and making it unusable. So my questions: - Are these schemes both still actively used? Are there data consumers who use these already? - What are the pros and cons of using them both in parallel? - Are there better ways of getting *all* of the information across without the redundancy introduced by using both schemes? Thanks, Chaos [1] http://wiki.openstreetmap.org/wiki/Key:turn:lanes [2] http://wiki.openstreetmap.org/wiki/Relations/Proposed/turn_lanes [3] http://josm.openstreetmap.de/wiki/Styles/Lane_and_Road_Attributes
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