Which description best defines a trailer in highway freight transport?

Which description best defines a trailer in highway freight transport?

• A. A container mounted on a tractor-trailer's frame
• B. A detachable freight carrying unit pulled by a tractor
• C. A wheeled box used on ships
• D. A trailer hitch accessory

Answer: (B)

In highway freight transport, a trailer is a detachable freight carrying unit that is pulled by a tractor. The key idea is that the trailer is a separate load-carrying body that can be attached to or detached from the tractor, using a fifth-wheel connection, so the tractor and trailer can work as a combined rig or be separated as needed. This distinguishes a trailer from a container fixed to the tractor’s frame, from maritime containers used on ships, or from a hitch accessory, which isn’t a freight-carrying unit at all.

In highway freight transport, a trailer is a detachable freight carrying unit that is pulled by a tractor. The key idea is that the trailer is a separate load-carrying body that can be attached to or detached from the tractor, using a fifth-wheel connection, so the tractor and trailer can work as a combined rig or be separated as needed. This distinguishes a trailer from a container fixed to the tractor’s frame, from maritime containers used on ships, or from a hitch accessory, which isn’t a freight-carrying unit at all.