No U-Turns on straight sections of road... map or unmap?

gpserror · 2019-11-18T18:35:07.000Z

Suppose there’s a bridge over water (or other section of road) where there isn’t a center divider. There’s a sign that says “No U-Turn”.

Does one map this?

Normally one waits until an intersection before making a U-turn because there’s some expectation of traffic temporarily going orthogonally to the expected travel direction. Plus it’s typically (but not necessarily) illegal to make these turns depending on locale.

I’ve seen people map these by splitting the way and using the endpoint as the via for the no U-turn though that endpoint isn’t really an intersection. Should these restrictions be removed from the data? If not, for consistency, no u-turns be added to the data if there’s a sign but no intersection?

escada · 2019-11-19T04:44:01.000Z

The navigation programs that I use have never said “make a u-turn” on such stretches. I doubt it has to be mapped. Apps should only request u-turns at intersections.

gpserror · 2019-11-19T07:55:12.000Z

Yeah, that’s what I would think. Normally U-turns are done where it’s possible to see a vehicle traveling orthogonal to your current direction for other reasons - this is at an intersection.

Now suppose someone did put it in, should these be removed? If not, how should programs that consume OSM treat these, should they simply be ignored (target application: mkgmap. Seems to give funny errors when it encounters these…)