[Tagging] Feature Proposal - RFC - Turn Lanes

[Ilya Zverev]

bkmap:
> It is not too late to change this. We must change about 11+2+7=20 
> tags worldwide if we consider to modify the notation of the 
> lanes:*:tag.

I'm strictly against global retagging. And it's impossible to 
unambigously resolve number of lanes to lane numbers in most of those 
cases.

> Using verbal values like left and right (except turn...) is IMO more 
> fault-prone than defined lane numbers. We need anyway suitable editor 
> tools for lanes.

Actually, this proposal was designed with the aim of not requiring 
special editors or plugins to mark turn lanes...

> It leaves open too many issues which could appear later: How to tag 
> the lane width, different surfaces and restrictions like  forbidden 
> lane change? How the data consumer knows, how the lanes of the  road 
> segments are connected together? And so on...

...and obviously, this implies some restrictions on tagging scheme: 
it's unpractical to add information for every lane into tags: there 
would be too many tags for each road segment. So in the proposal there 
are no properties for separate lanes: this can be impoved later, 
possibly with relations. For example, Tordanik is drafting out 
http://wiki.openstreetmap.org/wiki/Proposed_features/Lanes_as_Relations 
with exactly those points in mind.


IZ