Which vehicles must always be marked by their own lights or parking warning plates when parked on the roadway at dusk or in darkness in built-up areas?

In German traffic rules, trucks and motor caravans with a permissible total mass over 3.5 tons, as well as trailers, must always be marked with their own lights or parking warning plates when parked on the roadway at dusk or in darkness in built-up areas. This is to ensure they are visible and to prevent accidents since these larger or towed vehicles can be more difficult for other road users to see. Cars, however, do not have this strict requirement because they are smaller and usually have standard parking lights that suffice for visibility. Remembering this distinction helps ensure safety and compliance with parking regulations in urban areas during low light conditions.