A truck is a motor vehicle used to carry freight. Trucks transport a wide variety of cargo. They carry food to grocery stores and gasoline to service stations. Trucks haul manufactured products from factories to stores and, in some cases, to consumers' homes. In fact, trucks help transport nearly everything we eat, wear, and use. Some kinds of trucks are commonly called vans. The British word for truck is lorry.
Trucking is a major industry in developed countries. In the United States, for example, trucks haul about 75 percent of the industrial products and carry most of the goods moved short distances. Because of their speed and flexibility, trucks have come to carry a quarter of the intercity freight in the United States, and they enjoy an almost total monopoly in intracity freight delivery.
Trucks vary greatly in size and style. The smallest and most common type is the pickup truck. Another very common but much larger truck is the tractor-semitrailer, often called a semi or an 18-wheeler. The tractor is the front part of the truck. It contains the cab and engine, and it pulls the semitrailer. Some tractor-semitrailers also pull a second trailer and are called doubles or twin trailers. Triples consist of a tractor pulling three trailers.
Trucks are sturdily built to haul heavy loads. Most have engines that are more powerful than automobile engines. The engines of large trucks produce as much as 600 horsepower (375 kilowatts).
Large trucks typically have 9 to 18 forward gears and 2 or more reverse gears. The gears allow the engine to be used most efficiently so that the truck can reach and maintain desired speeds under varying conditions. Low gears make it possible for a truck to climb steep hills with a heavy load, while high gears allow it to accelerate to highway speeds.
Large trucks also have strong brakes, and large tires to handle the heavy loads. Some have multiple axles. Axles with heavy load capacity usually have dual pairs of tires.
Trucks have a wide variety of industrial, agricultural, and governmental uses. Some trucks have special uses.
From border to border, city to city, door to door, the roads of modern nations form the vital highway transportation systems that help keep them running. Trucks and truck lines form key links in such systems, helping people and businesses get the things they need for everyday living and working.
