Automobiles are self-propelled passenger vehicles used for transportation, usually with four to eight wheels and powered by an internal combustion engine using a volatile fuel. Other sources of energy include electricity and wind power, but the vast majority use petroleum fuel. The automobile has become the most common means of ground transport in the world. Its development was triggered by the increasing need for faster and safer travel. It has also greatly increased urbanization and the growth of associated industries like gasoline stations, restaurants, and hotels.
The first automobiles were powered by steam, but the modern automobile was invented in 1886 by Karl Benz. He improved on the steam-powered automobile by using a 4-stroke internal combustion engine and making it an industrial production model. This allowed him to sell automobiles at a price that was affordable for most people. He soon had competition from electric, gasoline, and diesel-powered vehicles, but the gas-powered automobile eventually became dominant in the 1910s.
In the 19th century, American manufacturers pioneered mass production techniques that enabled cars to be built at a much lower cost than European producers could achieve with their more complicated designs. Ford’s assembly line – in which workers stay at one station to do a single task while the car parts pass by on a conveyor – made the automobile affordable for most families.
Today’s automobile has evolved into a complex technical system with a wide range of subsystems that have specific design functions. These systems are constantly being upgraded to make the automobile more efficient, environmentally friendly, and convenient for users. The automobile is the most widely used vehicle in the world, with 5 – 60 million vehicles being produced each year and accounting for 25% of global road traffic.
Autos save time by enabling commuters to get to work and back in the same amount of time each day, shopping trips can be made quickly and economically, and visits to friends and family can be made at will. However, automobiles are not without drawbacks: They can be dangerous if they crash, and are a source of air pollution that contributes to climate change. Many urban areas have public transportation systems including buses (steam, diesel-powered, monorail or light rail), trains (steam, diesel, or electric), trams and subways that can move people more quickly and cheaply than automobiles when traffic congestion becomes a problem. Other forms of transportation such as bicycles and helicopters are available for people who live or want to travel more remotely.