2009/9/22 Anthony <[email protected]>: > It is possible to represent different surfaces and different maxspeeds > without using more than one way. "maxspeed:lane=130;110"; > "surface:lane=asphalt;concrete". That's not necessarily the best solution,
indeed, it won't be understood by none of the apps that are using our data and it doesn't say, which lane has which value... > Different turn-restrictions is already possible. If you have a three lane > way with two lanes going straight and one turning right, you join three ways > at one node: one with three lanes, one with two lanes, one with one lane. > If you have a three lane road with two lanes going straight and one lane > going straight or turning right, ditto, except the way going straight has > three lanes instead of two. Which lane is which is determined by the > geometry of the ways as they come out of the node. but that's exactly what I propose (map lanes explicitly) and it's against the separate-ways-only-when-physically-divided-paradigm (because an ambulance could change from one way to another)... >> but I also see the pros: >> - is easier to understand and more intuitive to edit: better >> maintenance: you see what is there > > That's an editor consideration. You can make it *look* like you're editing > three separate ways when you're really editing one way with three lanes. I knew someone would raise this argument, but please explain how the editor will know where the lanes exactly go. >> >> - is more precise in terms of positional accuracy > > I'm assuming the lanes are parallel. If not, then yes, you need to use > multiple ways. they will never be parallel for the entire lenght, at least there will be a start and an end, but often they will also turn at junctions... >> >> - can better represent stuff like ramps for motorways (parallel ways >> that currently are mapped like intersections), cyclelanes, ... > > Why are they being mapped like intersections? They shouldn't be. You mean > a gradual merge is being mapped at a right angle? That's wrong, and there's > no good reason for it (other than didn't have the time to get it right, > anyway). I meant the lanes for acceleration and breaking (when going on or from a highway). Usually there will be ~100mtres for this where you can change at any time, but in OSM you have to decide on one merging point. cheers, Martin _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
