semitrucks

A semitruck, or semi-truck, is a road freight vehicle configuration consisting of a tractor unit and a semi-trailer. The tractor provides propulsion, steering, and control, while the semi-trailer carries the cargo. The two parts are coupled using a fifth-wheel connection on the tractor that supports the front of the trailer; the trailer rests on its own landing gear and is largely unsupported by the tractor when not connected. This arrangement enables a single tractor to haul a variety of trailers and payloads, making it a common solution for long-haul transport.

Common trailer types include dry vans, refrigerated units (reefers), flatbeds, and tankers. In the United States, trailer lengths typically range from 28 to 53 feet, with a standard maximum gross vehicle weight around 80,000 pounds. Europe generally permits up to about 40 tonnes gross vehicle weight for articulated combinations. Weight distribution is managed through multiple axles and braking systems. The system supports standardized combinations across fleets and is a central component of intercity freight logistics, with capacity and distance driving scheduling and pricing.

Regulation and safety: operating a semitruck requires a commercial driver’s license (CDL in the United States; category C+E in many parts of Europe). Drivers and fleets follow hours-of-service rules and perform vehicle inspections. Vehicles are equipped with safety features such as anti-lock braking, electronic stability control, and auxiliary braking systems, and are subject to emissions standards and fuel-efficiency requirements. The semitruck remains essential for long-haul freight, enabling large-volume cargo movement over extensive routes.

History and context: the modern semi-trailer emerged in the early 20th century, with standardization and widespread adoption accelerating after World War II. Today semitrucks are a core element of global logistics and supply chains.