Are combination vehicles generally heavier and longer than single commercial vehicles?

Combination vehicles are indeed generally heavier and longer than single commercial vehicles. This is largely because combination vehicles consist of multiple parts, typically a tractor unit and one or more trailers. When fully assembled, these vehicles can reach significant lengths, often exceeding the maximum dimensions allowed for single-unit trucks, and they typically have a higher weight limit due to their design for carrying larger loads.

In contrast, single commercial vehicles are usually self-contained and do not combine with trailers, which limits both their weight and length. The design and purpose of combination vehicles allow them to transport larger quantities of goods over long distances, making them a common choice for freight transport.

The options suggesting that this is true only under specific circumstances—such as when fully loaded or only for certain types—are not as definitive as the assertion that they are generally heavier and longer. Thus, the straightforward answer is that combination vehicles, by nature of their construction, exceed the size and weight limits of single commercial vehicles by default.