Automobiles are wheeled motor vehicles that are designed to carry passengers, operate on roads and use an internal combustion engine or electric motor for propulsion. Usually they have four wheels and are powered by gasoline (petrol), although other fuels are used, and they come in many different shapes and sizes. Some are designed to be sporty or luxurious, others for towing or hauling large loads. Some are 4-wheel drive “off road” vehicles that can go places that other vehicles cannot.
The automobile revolutionized travel in the 19th and early 20th centuries. Steam, electric and gas-powered vehicles competed for decades, but the gasoline internal combustion engine won out by 1920. Henry Ford innovated mass-production techniques that reduced the price of his Model T until it became affordable for middle-class families. By the 1930s a few large American manufacturers controlled most of the industry. The automobile became an integral part of modern life, and Americans drove more than three trillion miles (4 billion kilometres) each year on average in their cars.
However, the automobile is a source of pollution and a drain on dwindling world oil supplies. In cities it creates traffic congestion that slows everyone, and it is expensive to maintain. People who do not have access to an automobile can still get around, but it is less convenient and usually takes longer. In most countries it is illegal to take another person’s automobile without the owner’s permission, and drivers are required to fasten their seat belts.