Marcus Wolschon wrote: > > If you have multiple lanes that lead to different locations > I suggest modelling them as multiple ways from the latest location > where a sensible lane-change is possible.
Sure, and that's what I do. But you want your directions somewhat before you get to the last location where lane-changing is possible. Quite often, there are signs indicating what lane you want to be in 1km or more before the last sensible lane-changing location. At this point, the road is still very clearly one road. You're legally, practically and easily able to change between the lanes. So it should be one way, with (say) lanes=4. Later, when it's split (at least for legal purposes - thick white lines, whatever), it's two or more ways. But I want to know which lane to be in now, as the overhead gantry is offering me a choice. So we need some sort of signpost recording system that lets me take the output of the nav system and correlate that with what I'm seeing on the overhead gantry. Here's an example: http://www.aidan.co.uk/md/LonM25J8Signs5404.jpg The last safe/legal/practical change of lane after that sign is half a mile (~800m) later. But (if need be) I want instruction about lane changes right now - or in fact 500m or so ago, so that the instruction is being reacted to just as this sign appears. Hence the need for some kind of signpost-recording system. Just for reference purposes, here's a commercial map provider's tagging of that same junction: http://tinyurl.com/6nkdwm -- Jon Bright Silicon Circus Ltd. http://www.siliconcircus.com _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/routing
