Automobiles, also called cars or motorcars, are wheeled vehicles designed for passenger transportation and powered by an internal combustion engine using a volatile fuel. They are typically driven by humans, but may be powered by electricity or by other means. Automobiles are widely used for transporting people and freight over long distances. They are much faster than walking or riding a bike for long journeys and can carry more passengers at one time than public transport such as buses, bicycles or trains, although they cost more and use more fuel than those modes of transport. Automobiles can also go places that are not easily accessible by other vehicles, and some types of automobiles have four-wheel drive to enable them to tackle difficult terrain.
The earliest automobiles were steam engines attached to wagons in the late 18th century, but they were slow and hard to control. Karl Benz developed a new kind of automobile, using a four-stroke engine fueled by gasoline, in 1885 or 1886. He patented the vehicle as the Benz Patent-Motorwagen. Gottlieb Daimler independently developed a similar automobile at around the same time. Daimler’s two-stroke engine was more powerful than Benz’s, and his vehicle could travel farther on each fill up of gasoline.
Early automobiles were expensive and only available to wealthy people, but the mass production method developed by Ransom Olds at his Oldsmobile factory in 1902 and greatly expanded by Henry Ford in 1910 allowed more Americans to buy cars. By the 1920s, many families owned a car. Automobiles have transformed societies by allowing for rapid long-distance movement and by enabling flexible distribution of goods. However, they can encourage sprawl – low-density development that degrades landscapes and causes traffic congestion.
Modern automobiles have many safety features. Seat belts reduce the number of deaths and injuries, and airbags can help prevent head or chest injury to occupants. More recently, crash-testing and engineering advances have led to vehicles that are less likely to roll over or be ejected from them.
An automobile is a complex technical system that has thousands of subsystems with specific design functions. Its performance, handling and stability are dependent on the way its weight is distributed over the chassis, the centre of gravity of the vehicle, the type and size of wheels, suspension characteristics, and the location of the engine.
Automobiles are convenient, and have made life more comfortable in many ways, but they can also be a significant source of pollution, which has serious health and environmental consequences. Despite these problems, people continue to depend on them. They can provide an emergency response to unexpected events such as a child falling sick, and they can save people considerable time by avoiding the need for lengthy walks in bad weather. However, some people prefer not to drive them or cannot because of physical limitations or a fear of driving accidents. There are also alternatives to the automobile, such as motorbikes and bicycles, but these have their own limitations.