Previously discussed means to same end
With exhaustive tagging of lanes=* these alone are sufficient for a "lane assistant" feature - which lanes turn and which don't is deducible from the geometry. Only some cases would require a tag on one section (node, even) to tell if a "new" lane starts, not at the edge of the road, but in between existing lanes, or simultaneously on the left and on the right. Alv 19:49, 23 August 2010 (BST)
- OK, you're right about the routing info. I had an exellent case to study and it is possible with the existing tags: http://maps.google.be/maps?f=q&source=s_q&hl=nl&geocode=&q=kortrijk&sll=51.080473,2.879542&sspn=0.00821,0.022724&ie=UTF8&hq=&hnear=Kortrijk,+West-Vlaanderen,+Vlaams+Gewest&ll=50.805982,3.270986&spn=0.004129,0.011362&t=k&z=17 . Sorry for the maps link, but yahoo doesn't provide good sattelite images. I won't use this to map but I know the way's anyway since I passed there every week. But what with the lanes:x:maxspeed? is that worthy of a proposal? or is it a duplicate? --Sanderd17 20:30, 23 August 2010 (BST)
- There was even a JOSM plugin at Proposed_features/lane_and_lane_group, but it seems it's not in widespread use. And it doesn't specifically mention it could store lane specific maxspeeds, but I recall thinking it could. Other than that, someone collected links to all kinds of proposals for "things offset from the center line" at Users:cmuelle8/multiple_way_tagging_on_single_geometry - looking at them now, many of them don't mention anything about specifying properties for those "virtual" elements.
- Anyway, the form lanes:1:maxspeed has been mentioned in some proposal, or mailing list discussion. There was opposing views about how to number the lanes, especially on twoway roads; all these have pros and cons:
- from "1" on the left always looking in the direction of the osm way
- from "1" the outer edge of the road if travelling in the direction of the way (lefthand/righthand traffic countries)
- from -n to -1, 0, 1 to n, zero being the center line, in the direction of the way (and again, would that vary between countries) Alv 07:33, 24 August 2010 (BST)