Which vehicles have to maintain such a great distance between them and the vehicle ahead when not inside a built-up area, that an overtaking vehicle can pull back into lane?

In Germany, larger vehicles like trucks over 3.5 tons and combination vehicles longer than 7 meters must maintain a larger following distance outside built-up areas. This increased distance ensures that other vehicles have enough space to safely overtake and then return to the lane without causing danger. Smaller trucks up to 3.5 tons are not required to keep such a wide gap. This rule helps improve road safety by allowing smoother and safer overtaking maneuvers around heavy and long vehicles.