What does this traffic sign indicate?

This traffic sign indicates a mandatory cycle path. In Germany, when you see this round blue sign with a white bicycle symbol, it means that cyclists must use the designated path. It is not optional; cyclists are legally required to follow this path for their own safety and the orderly flow of traffic.

Understanding this sign helps ensure that cyclists do not use the main roadway or sidewalks where cycling is not permitted. It helps separate different types of traffic and reduces the risk of accidents.

Remember, if you are cycling, always look for this sign to know when you need to switch to a dedicated cycle path. This is an important part of German traffic rules to maintain safety and clarity on the roads.