When must a car with trailer driving outside built-up areas on roads with only one lane for each direction keep a sufficient distance from the car in front so that an overtaking vehicle may pull in?

In Germany, when driving a car with a trailer outside built-up areas on roads with only one lane in each direction, you must keep enough space behind the vehicle in front if your vehicle combination is longer than 7 meters. This rule ensures that a faster vehicle coming from behind can safely overtake and pull back into the lane without causing danger or obstruction. The 7-meter length is important because longer vehicle combinations need more room to maneuver, so maintaining sufficient distance helps prevent accidents and keeps traffic flowing smoothly.