If you see a round, red framed sign you shall be aware of a prohibition.
Don't exceed a certain speed ! It's the sign with the black number in the white inner circle.
The basic sign - round, red framed with a white empty inner circle - means prohibition for this road to all vehicles, exceptions are made clear by an additional sign, basicly a rectangular white sign with a small black frame and the info "Anlieger frei", meaning for residents and visitors free.
The other prohibition signs give the details by the symbols in the inner white circle.
Examples:
#1 Pedestrians mustn't use the road. (valid for some off city roads or fast traffic roads, autobahns are off-limits, too)
#2 Bikes mustn't use the road.
#3 Cars and motorbikes mustn't use the road.
Really important are the signs:
#1 Don't pass motor vehicles with more than two tires. You are allowed to pass a motorbike but the motorbike mustn't pass a car.
#2 Trucks mustn't pass motor vehicles with more than two tires.









