What is the regulation concerning carrying persons in a trailer while traveling on a highway?

Carrying persons in a trailer while traveling on a highway is prohibited at all times for safety reasons. This regulation is in place to protect passengers who would be in a trailer, as it does not have the necessary safety features, such as seat belts and proper structural integrity, to ensure their safety in the event of a collision or sudden stop.

Trailers are not designed for human transportation; they are intended for cargo. Allowing individuals to ride in a trailer increases the risk of severe injury or fatalities due to the lack of protection that a vehicle provides. Traffic rules emphasize the importance of safety for all road users, and prohibiting passenger transport in trailers aligns with these safety priorities.

The other options suggest scenarios that imply some allowances for passenger transport in trailers, which do not align with established traffic regulations. Therefore, the regulation is clear: transporting people in a trailer is not permitted under any circumstances on highways.