(road transportation) A truck trailer without sides or ends designed to transport oversize cargo that normally would not fit into standard freight trailers. These trailers are also known as gooseneck or low-deck trailers. Drop-deck trailers are distinguished from standard platform or flatbed trailers by having a lower platform height. This enables the trailer to carry taller loads, and often very heavy loads that would be top-heavy on a standard platform trailer. Drop-deck trailers are especially used for the transport of goods that must be loaded from the side, top, or rear of the trailer. Standard cargo for drop-deck trailers includes: ocean freight containers, large oversize machinery, heavy and oversize construction equipment, lumber, plywood, steel, pipe, and rebar.