Two vehicles approach one another at an intersection. Both vehicles want to turn left. In what exceptional case do they have to turn one after the other?

The combination of answers you selected is correct because it reflects essential scenarios dictated by German traffic regulations when two vehicles want to turn left at an intersection.

1. "If the road traffic situation demands it" is relevant because in some situations, such as high traffic volumes, it may be safer for vehicles to take turns rather than risk a collision.

2. "If the layout of the intersection demands it" is crucial as certain intersections may have specific configurations that require vehicles to yield to one another for safety and smooth traffic flow.

Together, these points highlight the need for drivers to assess both the dynamic traffic conditions and the physical design of the intersection to make safe decisions. The German traffic rules are designed to prioritize safety and efficiency, ensuring that drivers are aware of their surroundings and act accordingly.