What do you do when you see this traffic sign?

The traffic sign you see indicates that vehicles must turn left. According to German traffic laws, when you encounter this sign, you are required to signal your intent to turn left (indicating left) and then proceed left only. This ensures clear communication with other road users and maintains the flow of traffic.

By following this sign, drivers help prevent confusion and potential accidents at intersections. It's important to comply with both signaling your intention and executing the left turn, as neglecting either can lead to violations of traffic regulations.