Automobiles are wheeled vehicles that carry passengers. They are designed to run primarily on roads and have seating for one to seven people. Almost all automobiles have an internal combustion engine that burns gasoline or other fuel to power the motor. The engines may have from four to eight cylinders, or a series of small combustion chambers connected by camshafts. Each cylinder has a piston that moves up and down to create a combustion cycle, a process that converts gas into energy. The resulting energy turns the crankshaft, which in turn drives the wheels of the automobile.
The automobile has transformed modern life. It has made work possible in places that could not support a large workforce, and it has brought leisure activities and new services like hotels, restaurants, amusement parks, and fast food chains. But the automobile has also brought harm to the environment with its emissions and the use of undeveloped land for highways. It has also created the need for new laws, including safety features and driver’s licenses.
In the United States, cheap raw materials and a tradition of industrial manufacturing helped make automobiles available to middle-class Americans. Production techniques like the ones developed by Henry Ford enabled automobile companies to manufacture cars in great numbers and reduce their prices until they became affordable to many families.
With a population far larger than Europe’s and a vast hinterland of scattered settlements, the United States had a greater need for automotive transportation than most nations. This, along with the absence of tariff barriers, encouraged early American car manufacturers to seek economies of scale and develop mass production.
As the automobile came to be used by the general public, engineers worked to improve its performance, comfort, and safety. Research and development teams focused on such areas as engines, transmissions, braking systems, electrical systems, air conditioning, and steering. Improvements to these systems helped to increase the speed and range of automobiles. They also improved the reliability of automobiles and lowered their operating costs.
Today, automobiles have evolved to a point where it would seem nearly impossible or at least highly inconvenient to live without them. In the United States alone, more than three trillion miles (five trillion kilometers) are driven each year by automobiles. In addition, the automobile has influenced society in other ways, from the emergence of suburbia to the development of leisure industries.
While the automobile has become a fixture in most American lives, there are some places where it is still not common. In rural areas, some residents still prefer to travel by foot or on horseback rather than by automobile. Others prefer to use public transportation, which is available in most cities and towns. Still, for millions of people, the automobile is the primary means of transportation. It allows them to get where they want, when they want, without having to deal with the problems of traffic or the nuisances of public transportation. This is especially true in areas where jobs are farther from home.