This is not a technical question, but rather one of convention.
How should divided highways be mapped? I am not really happy with either of the two obvious options.
a) Show as a ‘normal’ primary or secondary road, however this does not show the restrictions on crossing the painted divider except at the designated crossing points.
b) While a dual carriage way gives the correct restrictions a divided highway does not ‘look’ like a dual carriageway, and has problems with turnoffs on the ‘wrong’ side of the road. This does raise a corollory question.
c) How are such dual carriageway turnoffs handled?
Which approach is ‘correct’. or is there another preferred option?
Thanks again for the invaluable help.
The general consensus is that you draw a line for each separate physical feature. So if your highway is physically divided you draw two separate lines, otherwise just one.
On the subject of turnoff handling: there is much to be improved in OSM. There are some propositions on how to handle them, but no consensus has been achieved. Currently there is a big discussion on how to handle e.g. turnoffs better (and many other advanced relationships), so I think it’s best to be patient and wait with implementing turn restrictions until a proper infrastructure is in place.
so basicalay when i create a “way” i should draw 2 ways (one for each direction + the walkways ) ?
ps: oops … or DOH!
Looks like you’ve found the answer yourself already, but:
No, it’s not necessary to map a walkway directly besides a way (it is assumed that pedestrians can walk on certain types of roads). If a walkway is separated from the way by e.g. a patch of grass you can choose to draw that walkway as highway=footway.