Box semi-trailers can be divided into passenger box type and cargo box type based on the shape of the cargo box. Passenger box type semi-trailers generally have an integrated structure of cargo box and cab, such as ambulances. Cargo box type semi-trailers generally have a separate structure of cargo box and cab, such as box-type less-than-truckload (LTL) transport vehicles.
Based on specific functions and structures, they mainly include refrigerated semi-trailers, wing-opening box semi-trailers, curtain-side transport semi-trailers, and container transport semi-trailers. Wing-opening box semi-trailers have advantages such as fast loading and unloading speed, high efficiency, and the ability to load and unload from the side. Container semi-trailers have a standard container structure for the cargo area, allowing for long-term and repeated use and adaptability to multimodal transport.
The common standard length for semi-trailers is 13 meters, but there are also various specifications such as 10 meters, 11 meters, 13.75 meters, 14.6 meters, 15 meters, 16 meters, and 17.5 meters. National regulations stipulate that the total length (including the tractor unit) must not exceed 17.5 meters.
