[Tagging] bicycle=use_sidepath applicable to bicycle lanes?

[Hubert]

Hallo Volker,

there is not accepted method to denote that a way is mandatory to use by bicyclists, however there are some proposals ([1],[2]) for that. It’s only possible to tell a cyclist to stay off a carriage way by tagging “bicycle=use_sidepath” on the central osm-way. There a few interpretations to this.
1. “bicycle=use_sidepath” can only be used if there is a separately drawn sidepath (highway=cycleway/path/footway) present. This is how it was intended, as a weaker alternative to bicycle=no. It basically tells a router not to use a way and look for alternatives unless there is none, or it "cost" way too much time. As where bicycle=no tells a router to never ever use that way.
2. “bicycle=use_sidepath” can also be used if there is an additional "cycleway=lane/track" tag. It basically tells a router to not use this way unless there is also a "cycleway=lane/track" tagged.

IMHO we should only use it according to the first interpretation.

Now to your questions:
> A) In the case of a road with two cycle lanes with mandatory use (they do have the official 
> cycle path signs - case L1a in http://wiki.openstreetmap.org/wiki/Bicycle) how do I tag 
> correctly the mandatory use on the highway:
> 1) by bicycle=use_sidepath 
> 2) by bicycle=use_cyclelane (or bicycle=use_sidelane?)
Neither one. If the mandatory use is due to the presence of a traffic sign, you can tag the traffic sign itself. highway=* + cycleway=lane + cycleway:traffic_sign=*. (This is useful anyway).
You can also use one of the proposals [1] or [2]. The first one is "safer". Or you can use the distinction between cycleway:bicycle=official/designated ; cycleway:bicycle=official/yes or cycleway:bicycle=designated/yes. The last one is most common in Germany and Poland as far as I know, but it also has it's disadvantages.

> B) In the case of a oneway road with one mandatory opposite-direction cycle lane (they do
> have the official cycle path signs in the direction opposite to the car flow - case L1a in 
> http://wiki.openstreetmap.org/wiki/Bicycle)?
> bicycle:backward=use_sidepath (or use_cyclelane or use_sidelane)
> plus
> bicycle:forward=yes (or bicycle:forward=share_carlane?)
Did you mean case M3b?
If so you can use
highway=* + oneway=yes + oneway:bicycle=no + cycleway:right=shared_lane + cycleway:left=lane + cycleway:left:traffic_sign=* (+ cycleway:left:bicycle=official/designated).

> Volker
> (Italy)

Sorry, but there is no simple answer.

Yours Hubert

[1] https://wiki.openstreetmap.org/wiki/Proposed_features/Obligatory_access_suffix
[2] https://wiki.openstreetmap.org/wiki/Proposed_features/obligatory_usage