What is the maximum permissible length of the truck and trailer with load?

You answered correctly: The maximum permissible length for a truck with a trailer, including the load, is 20.75 meters.

This rule is set by German traffic regulations to ensure road safety and maneuverability, especially on tight roads or curves. Trucks and trailers that exceed this length could pose danger to other traffic and face restrictions on where they can drive. Always make sure the total length, measured from the front of the truck to the end of the trailer, including anything loaded, does not exceed 20.75 meters. This helps maintain traffic flow and prevents accidents.