What does this traffic sign indicate?

This traffic sign indicates the end of the autobahn (motorway). In Germany, the autobahn is a special type of highway with specific rules, such as no general speed limit and particular regulations for entering and exiting. When you see this sign, it means you are leaving the autobahn, so the special privileges and rules that apply to the autobahn no longer hold beyond this point.

After this sign, normal road rules apply again, such as speed limits and other traffic regulations typical for regular roads. This sign helps drivers prepare to adjust their speed and driving behavior accordingly.