Automobiles are wheeled passenger vehicles that carry their own motors and are designed for the transport of people rather than goods. They are designed to run primarily on roads, seat one to six people and have four wheels. There are over 590 million cars worldwide as of 2002 (roughly one car for every eleven people), and they serve many different purposes ranging from providing mobility to industrialists, police forces, ambulance services, and private citizens to such personal uses as vacation travel and shopping. The development of automobiles has also had a tremendous impact on cities, and on the economic structure of nations. Automobile production is a major industry, providing jobs in manufacturing and the manufacture of ancillary products such as tires, batteries, and engines. Mass production techniques developed for the automobile industry in the early twentieth century have become standard throughout all manufacturing industries.
The automobile revolutionized American society by providing the means of rapid transportation for vast numbers of people over long distances. It created new industries and reshaped the entire economy. It sparked new social movements and helped to define a new era in American history that could be called the “Automobile Age.”
While general conditions such as the expansiveness of the nation and a poorly developed urban transit system held back the use of motor vehicles for a time, mass production of gasoline-powered automobiles allowed automobiles to come to market that were modestly priced, easy to maintain and operate, fast and able to travel long distances, and powered by a cheap, widely available, easily accessible source of energy. Entire societies have been restructured around these automobiles, and whole industries have sprung up to provide the accessories, maintenance, and repair of them.
A key component of automobiles is their chassis, which provides the base for all other systems and components. The arrangement and choice of these depend on the specific needs and purposes of an automobile. For example, an automobile built to drive on a variety of road surfaces must have a durable suspension system that can withstand extreme loads and harsh operating conditions. A sporty automobile, on the other hand, requires a more sophisticated system that optimizes high-speed handling and stability.
Similarly, the body of an automobile provides room for passengers and storage, supports the other systems, protects the vehicle from the elements, and gives the car its distinctive appearance. The body varies depending on the type and purpose of an automobile; for instance, front-wheel drive allows for a smaller, lighter chassis, while independent suspension for all four wheels improves safety and comfort at higher speeds.
Other essential systems include the engine, transmission, and brakes, all of which are designed to maximize performance and minimize maintenance requirements. Finally, the electrical and instrumentation systems control the operation of all automobiles and determine their safety, comfort, and reliability. In addition, the fuel and exhaust systems are crucial to the operation of automobiles, while the ventilation, cooling, and air conditioning systems regulate interior temperature and humidity.