Which of the following is not included in the official definition of a semi-trailer?

The official definition of a semi-trailer includes specific characteristics that accurately describe its design and function. The aspect that is most pertinent is that a semi-trailer is designed to be towed by a truck or tractor, indicating that it is engineered specifically for this purpose, reflecting the relationship between the tractor unit and the trailer.

In addition, a semi-trailer must carry part of its load on its own wheels, further emphasizing its unique construction compared to other trailers. This feature enables the semi-trailer to function effectively in conjunction with the towing vehicle, ensuring stability and weight distribution during transport.

Furthermore, a semi-trailer is inherently attached to a motor vehicle for transportation, as it cannot operate independently. Therefore, specifying that it must be connected to a motor vehicle is vital to its definition.

The first statement about having axles at its front or rear ends is misleading in the context of the semi-trailer’s definition. A semi-trailer primarily has its rear axles and is supported at the front end by the towing vehicle, thus not strictly needing axles at both ends. This nuance makes it clear that option A does not accurately represent the standard definition of a semi-trailer.