In Germany, what does a blue rectangular Autobahn sign identify?

In Germany, a blue rectangular Autobahn sign identifies a motorway. The sign marks entry to or direction toward a road intended for high-speed, access-controlled traffic.

German Autobahnen generally have separate carriageways, controlled access and grade-separated junctions. Pedestrians, bicycles and many slow vehicles are not permitted on them. Blue is used for motorway-related direction and route information, helping distinguish these roads from ordinary route classes.

The word Autobahn is often associated with unlimited speed, but that is an oversimplification. Some sections have posted limits, and drivers must always obey displayed restrictions, temporary work-zone controls and conditions-based duties of care.

Germany’s blue motorway signs can be confused with blue mandatory signs, which are often circular and require a specified movement or road use. Shape matters: the rectangular blue sign is informational or directional, while a blue circle usually communicates an obligation.