The sign you mentioned, "Arrow signposts on federal highways," typically indicates the direction in which the road continues or provides guidance for navigating junctions on federal highways. These signs are important for helping drivers understand the correct path they should take, especially at intersections or points where the road splits into different directions.

In Germany, these signs often include arrows pointing straight ahead, left, or right, and are used to help manage traffic flow and ensure that drivers can easily navigate complex road systems. It's essential to follow these signs to adhere to traffic regulations and maintain safety on the road.

If you have any specific questions or need details about a particular situation involving this sign or others, feel free to ask!