Rob wrote: > I don't see this. Right and Left tell you where the lane is, but it does not > tell a user (or routing software) which direction you can ride in. This > requires knowledge of which side of the road each country drives on > (or forward/backward tags).
Ah, yes. I see your point. I was trying to say that you need left/right to say where the cycle lanes are relative to the way to render them in the correct place, but I can see that that doesn't tell you which way you can cycle along them. Similarly just drawing a way on its own doesn’t tell you which side you drive on, though there are oneway tags to cover this (or routers can assume 2 way and not care which side). The alternative of cycleway:forward tells routers that you can cycle in the direction of the way (or the opposite way for cycleway:backward), but doesn't tell renderers whether this should be rendered to the left or the right of the way. I guess this all relates to the issue with tagging lanes; if a road is tagged lanes=3 how do you say how many are forward and how many are backward? I think various proposals keep being made, but I'm not sure anything has been settled yet? I wish I hadn't started thinking about this now, as I think of scenarios that I've never encountered in reality: * twoway cycle lanes to one side of a twoway road * cycle lanes that are oneway, but opposite direction to the adjacent traffic lane (would this be cycleway:side=-1) Certainly the tagging scheme for cycle lanes only really handles the basic rendering case, I think, and requires knowledge of which side of the way people drive for the simple routing case. And doesn't even make clear whether it is the sort demarked with a solid or dashed line (though perhaps there is something about this in the wiki somewhere). Ed _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-gb
