Automobiles are four-wheeled vehicles that use an internal combustion engine fueled by a volatile fuel such as gasoline. The engines power the wheels through transmissions, which have gears that can shift to change speed and direction. Automobiles are now one of the world’s most common forms of personal transportation, and they are the primary means of transport in many cities, towns and rural areas. The automobile has revolutionized the way people live and work, making it possible to travel long distances in a very short amount of time.
Automobile production began with gasoline-powered engines in the late 19th century, led by the American manufacturers William Durant and Henry Ford. They developed the first affordable mass-produced cars, and the new manufacturing methods that they introduced to industrial production greatly reduced the cost of car ownership. These included the assembly line, in which workers perform a single task and the car parts move on conveyer belts. The modern automotive industry is now dominated by a few major corporations that control most of the market share.
There are many different types of automobiles, including passenger cars (cars and buses), cargo cars, special cars such as fire trucks, sanitary vehicles, mobile crane vehicle, or refrigerator truck, and off-road cars that can drive on rocks, etc. There are also sports cars and racing cars. The modern automobile has many safety features to protect passengers from accidents, and they are mandatory in most countries.
In the United States, automobiles are used for the majority of commutes and are the main mode of family transportation. Americans drive more than three trillion miles (five trillion kilometers) every year, and the automobile has become one of the nation’s largest industries. It has helped to create new service industries such as restaurants and hotels, and it has also encouraged participation in outdoor recreation. It has eliminated rural isolation and brought urban amenities such as medical care and schools to rural areas.
The modern automobile contains thousands of components, and its design is a complex technical system. Some of the subsystems are driven by design functions that were determined by market trends and social concerns, while others have evolved from breakthroughs in technology such as computerized engine controls and high-strength plastics. Most recently, the automotive industry has focused on developing new engines that can be powered by renewable fuels such as biomass and biodiesel. Some of these engines can achieve better gas mileage than traditional cars, and some even run on hydrogen. They can also operate without the need for a cooling system and can be driven for extended periods of time on steep hills or in bad weather. This technology may eventually lead to the development of a fully automated vehicle that can drive itself on highways or other roads. This will reduce the number of automobile accidents and pollution caused by human error. It may also make the car more useful for people who cannot drive or have disabilities.