What is the best way to draw and tags when the road is 2+2 ways but without central separation, like this : http://maps.google.fr/?ie=UTF8&ll=48.063712,1.875572&spn=0.020593,0.038581&t=m&z=15&layer=c&cbll=48.062754,1.876849&panoid=kZulMiKZfTy3txpyzwRo7Q&cbp=12,0,,0,0 There is to possibilities : 1/ Draw 2 highways tagged oneway=yes 2/ Draw 1 highway tagged lanes=4 What is the best way to do ? I don't found any information about this. asked 14 Feb '12, 12:04  zewan |
One Answer:
Possibility 2 is the right one: The best way is to draw only one highway if there isn't a central separation. And you're right, the tag lane is the good one for indicating the number of lanes. See also the doc about trunk. answered 14 Feb '12, 13:02  NicolasDumoulin |
It is also depending on country specifications, e.g. here:
See https://wiki.openstreetmap.org/wiki/DE:Germany_roads_tagging
In Germany, outside of built-up-areas, a continuous double line counts as "physical separation", which has effects on the allowed maxspeed.
In most cases, possibility 2, as Nicolas wrote, is the way to go. But don't forget to add turn restrictions at intersections (four times no left at every four-way intersection, where the line is not broken)