What does this traffic sign indicate?

This traffic sign is a warning sign indicating that there are traffic lights ahead. In German traffic rules, such a triangular warning sign with a red border alerts drivers to prepare to stop or give way if the traffic light is red. It helps drivers anticipate a signal-controlled intersection or pedestrian crossing ahead, ensuring they approach carefully and be ready to obey the traffic light signals. Recognizing this sign helps you slow down and be attentive to the upcoming traffic lights.