Which of the following best describes a combination vehicle?

A combination vehicle is best described as a truck-tractor that pulls one or more trailers. This definition is crucial in the context of commercial driving because it identifies the specific type of vehicle that drivers of combination vehicles will operate. A truck-tractor is designed to couple with trailers, allowing it to transport larger loads and making it suitable for specific tasks that require multiple trailers or heavier cargo.

The other definitions do not accurately encompass the characteristics of a combination vehicle. While some vehicles may operate only on highways, this does not capture the essence of a combination vehicle. Similarly, a vehicle shaped like a bus or a compact vehicle transporting goods does not reflect the structural design and function of a truck-tractor with trailers. Understanding this definition is important for driving and safety regulations that apply specifically to drivers operating combination vehicles in Virginia and beyond.