Hey there,
Could anybody tell me how to tag restrictions as seen here?
osm.org/?lat=47.653834&lon=9.483013&zoom=18&layers=M
Just guess you are on Paulinenstraße and want to get to Bismarckstraße.
Any routing-software will tell you to turn left on Ailingerstraße, and where the two Ailingerstraße-branches meet, turn left again onto Ailingerstraße (basically a U-turn, but not in the routing data..). Then turn right on Bismarckstraße.
However in reality, you would take the Löwentalerstraße, Charlottenstraße and then turn left into Ailingerstraße again.

How to you tag restrictions like that? There is no "no left turn" sign where the Ailingerstraße-branches meet. However, any routing-software who tells you to make some kind of u-turn there would seem stupid.

Thanks.