The sign you asked about is known as "Tourist Route as a Guide Preliminary Guide Left-Turning."

This sign indicates that a tourist route is approaching, and it is specifically designed for vehicles that will need to make a left turn to access this route. The purpose of these signs is to assist drivers in finding scenic or popular visitor spots, typically aimed at tourists who may not be familiar with the area.

When you see this sign, it is important to prepare for a left turn and to be aware of any traffic conditions that may affect your ability to make that turn safely. Always ensure that the intersection is clear and that you are following all other traffic rules while making the maneuver. Keep an eye out for any additional signs or directions that may provide further guidance on the tourist route.

If you have any more questions about German traffic rules or need assistance with other signs, feel free to ask!