An automobile is a passenger vehicle that moves under its own power and is usually powered by an internal combustion engine, most often using gasoline (petrol), but also diesel fuel, electricity, steam, or natural gas. Its chassis and body, analogous to the skeletal structure in the human body, support systems for braking, steering, suspension, and the driver’s seat. The car’s design must balance performance, safety, and comfort for a variety of different uses.

Automobiles have radically changed the way we live. They have transformed our cities and towns, reshaped transportation, and altered the economy of many countries. They have allowed individuals to travel across the country in a few hours, and to visit long distances with ease. They have restructured society by creating new industries and services to supply the vehicles, including highway construction, oil refineries, and dozens of new jobs in a wide range of industries that produce everything from rubber to vulcanized petroleum products and plastics to auto parts and repair shops.

Automobile technology has advanced dramatically since the first models were built in the late nineteenth century. Karl Benz is credited with inventing the first automobile, and Henry Ford revolutionized production methods by developing the assembly line. Today, there are more than 70 million cars in operation worldwide, and a wide variety of designs, from small, efficient cars to high-performance sports models.

The automobile has had both positive and negative social effects. Its convenience has encouraged families to vacation in places where they could not previously have traveled and helped revitalize resort towns. It has encouraged urban dwellers to shop in town and suburban people to rediscover pristine landscapes. It has brought with it pollution, traffic congestion, and demands for road safety features and licensing at the state level.

Automobiles have been a significant contributor to sprawl, the development of low-density suburban areas that waste open space and create traffic jams. They have enabled people to shop at stores and markets that once would have been impractical to reach, but they have also made it possible to transport goods and services far from their points of origin, which has contributed to the growth of trucking as a major industry. They have lowered housing costs and increased personal freedom, but they have also introduced problems such as pollution and a drain on world petroleum supplies. The higher unit profits that the automobile industry has earned on its gas-guzzling “road cruisers” have come with a price in the form of lower standards for automotive safety, emission control, and energy consumption. They have also contributed to an imbalance between the needs of the manufacturing sector and the demand for vehicles by consumers. These imbalances have begun to be corrected in recent years as the automotive industry has shifted toward more functional design and production techniques.