18wheelers

An 18-wheeler, also known as a semi-trailer truck or tractor-trailer, is a combination vehicle consisting of a prime mover (tractor) and one or more semi-trailers. These vehicles are essential for long-haul freight transportation in North America, moving a significant portion of the continent's goods. The "18-wheeler" designation refers to the typical number of wheels found on such a rig: two axles on the tractor, each with dual wheels, and multiple axles on the trailer, also usually with dual wheels.

The tractor unit is powered by a large diesel engine and houses the driver's cab. It is equipped with fifth-wheel coupling that connects to the semi-trailer. Semi-trailers come in various configurations, including dry vans, flatbeds, tankers, and refrigerated units, each designed for specific types of cargo. The immense size and weight of 18-wheelers require specialized driver training and adherence to strict safety regulations.

Operating an 18-wheeler involves complex maneuvers due to their length, weight, and turning radius. Drivers must possess a commercial driver's license (CDL) and often undergo extensive training to handle these vehicles safely. Factors such as braking distances, blind spots, and weather conditions significantly impact driving. The trucking industry plays a crucial role in the supply chain, facilitating the movement of raw materials, manufactured goods, and consumer products across vast distances.