You are driving a vehicle with a gross vehicle weight rating of 7 t at 60 km/h outside of a built-up area. When do you have to maintain such a great distance, that an overtaking vehicle can pull back into lane?

Your answer is correct because German traffic rules require drivers of heavy vehicles (over 3.5 tons) traveling outside built-up areas at speeds over 50 km/h to maintain a sufficient distance if there is only one lane in their direction. This distance ensures that an overtaking vehicle can safely return to the lane in front of them. If there is more than one lane, the overtaking vehicle can use another lane without needing extra space, and if overtaking is prohibited, the rule about spacing for overtaking does not apply. Therefore, the key factor is having a single lane in your direction to allow safe re-entry of overtaking vehicles.