Who is required to indicate a change of driving direction here?

In this scenario, all three parties involved—the driver (you), the red car, and the motorbike—are required to indicate a change of direction. According to German traffic laws, all vehicles must signal their intentions when turning or changing lanes to ensure that all road users are aware of each other's movements.

This is important for safety and communication on the road, preventing misunderstandings and potential accidents. By signaling, you inform others of your actions, allowing them to adjust their behavior accordingly. In this case, since you and the other two vehicles are all involved in navigating the intersection, it is crucial that everyone indicates their direction clearly.