Automobiles are a large and important segment of the world’s transportation system. They transport people, goods and services over land. They carry more freight than all ships, trains and aircraft combined. They are a key factor in the global economy, giving access to jobs and services that would be difficult or impossible to get without them. They provide a level of personal freedom and mobility not possible with other forms of transport, and they help create and support industries such as automotive manufacturing and road construction.
Automobiles use a complicated set of mechanical systems to power and control the vehicle. These systems include the engine, transmission, chassis and bodywork. They also use electrical equipment and service devices. Most automobiles burn a fuel, usually gasoline (or “gasoline” in American English), to make the internal combustion engine run. The engine converts the fuel to energy that turns the wheels of the car and provides electricity for lights, radios, etc. The energy from the engine is transferred to the wheels by a transmission, which has a series of gears that can change the speed of the wheels.
The earliest cars used steam, battery power or an internal combustion engine powered by gunpowder. The steam-powered car was able to travel fast and was a practical form of transportation, but it had a limited range and required a long time to start. In 1804 Oliver Evans built the first self-propelled car in the United States, which was actually a harbor dredge scow fitted with steam engines and wheels. Cugnot’s self-propelled steam carriage, which was capable of traveling on land and via paddle wheel in the water, followed in 1806.
Inventors and manufacturers have been working to improve and refine automobiles ever since. Many of these improvements have come from research and development engineers, who design new technologies to make vehicles more comfortable, reliable, safe and economical to operate. These innovations have been based on the physics of vehicles, their mechanics and operating environments.
The modern automobile revolutionized everyday life in the early 20th century. It allowed families to live farther from work, creating a growing middle class that could afford cars. As a result, more families were able to participate in outdoor recreation such as camping and fishing, and cities and towns developed services such as restaurants and hotels to cater to them. In addition, the invention of assembly line techniques by U.S. car maker Henry Ford allowed automobiles to be produced at affordable prices and democratized personal transportation.
Today, millions of people around the world own and operate cars. Many more work in factories producing automobiles and in the many businesses that supply them, such as auto parts and gas stations. But automobiles also cause problems such as air pollution, traffic congestion and accidents. People die from these problems every year, and millions are injured. Some of these injuries and deaths are the fault of other drivers, but some are caused by malfunctioning or poorly maintained cars.
