I’d map that as a cycleway:right=lane; cycleway:right:oneway=yes. Notwithstanding, that doing so, might make casual cyclists end up there. To consider hazards is not fun: Imagine a family with kids on holidays getting routed there. This especially, when realizing that openstreetmap data gets used as the one and only source of information more often than welcome.

Back on Topic: In a Vienna Convention country, this might very well carry a mandatory sign, the meaning of would be, people are to cycle on the designated lane, and not on the carriage way there. There really is not more to this. Anybody disagrees?