A wide array of trucks occupies the roads, from big semis towing loads from coast to coast, to luxury SUVs with satellite radio and buttery-leather seats. One thing is sure; trucks are a major influence on a country's ability to get goods and services to consumers, and therefore are an important part of the economy. Trucks come in various shapes and sizes, and serve myriad purposes, the most popular purpose being the movement of large amounts of cargo. Trucks can be configured to lift, tow, pull, and support specialized equipment.
Trucks are large and powerful, for the most part. The smallest versions are similar to the automobile, particularly the sport utility vehicle. Trucks run on either gasoline or diesel fuel, with diesel being the dominant fuel.
Trucks are generally categorized into three main weight classes: light-duty, medium-duty and heavy-duty. Above heavy-duty are very heavy trucks and transporters for moving over-sized loads (heavy haulers), and off-road heavy trucks, which are used for mining, foresting and construction.
As technology has advanced, the truck has evolved from the rudimentary steam-powered horseless carriage of the 19^th century to the big, powerful diesel engines and complex suspension, transmission, steering and braking systems seen in today's rigs. Trucks can go where trains cannot; and can maximize each trip with large payloads. After World War II and certainly by the 1950s, trucks were designed with a focus on peak performance. Manufacturers like Cummins in the US, Perkins in Britain and Volvo in Sweden began to respond with innovations in comfort and engineering.
The importance of trucks to the economy can be illustrated by the recent rise in fuel costs. The effects of fuel prices and availability can be felt in nearly every industry that relies on trucks to do business, from small local businesses to big conglomerates. If the cost of fuel goes up, businesses are forced to increase their prices to accommodate higher shipping costs. The increased costs are passed on to the consumer.