I found this kind of cycle barrier in Oldenburg right here:
There are 2-3 similar barriers in the same region.
Problem: there is no design specified in openstreetmap fitting for those. How can this be solved?
(I mean the list below “Types / designs of cycle barriers” here: Cycle barrier in OSM Wiki )
I reckon single here means, the obstacle is a single line (seen from above). Compare to double and triple illustration where the obstacle is two or three “lines”.