What do such traffic signs indicate?

The traffic sign you see is a blue hexagonal sign with the number 48, which indicates the number of an autobahn (motorway) in Germany. Autobahn signs are specifically designed to inform drivers about the specific motorway they are on or approaching.

In Germany, each autobahn has a unique number, and these signs help with navigation and orientation on the road network. Understanding these signs is crucial for safe driving and for knowing where you are going, especially on longer journeys.

You can recognize that this sign does not provide information about the distance to services or the identification of European roads, but is solely focused on the autobahn designation.