What does this traffic sign indicate?

The sign indicates a speed limit of 30 km/h in that zone. This means that vehicles are not permitted to exceed this speed limit. The "30 ZONE" sign signifies a designated area where this maximum speed applies, typically to enhance safety, particularly in residential areas, near schools, or in places with high pedestrian traffic.

In terms of the German traffic rules, this speed limit is aimed at reducing accidents and ensuring the safety of pedestrians and cyclists. It's crucial for drivers to adhere to this limit to avoid penalties and contribute to a safer driving environment. Understanding these regulations helps in recognizing the importance of speed limits in maintaining road safety.