Automobiles are vehicles for the transportation of people and goods. They are powered by an internal combustion engine that uses a volatile fuel to produce mechanical energy for propulsion. They use four to eight tires and are typically constructed of metal or other light-weight materials.

Modern life would be inconceivable without automobiles. They have reshaped economies, transformed cities and suburbs, and changed lifestyles. But they have also brought many harms. Automobiles can cause accidents and lead to air pollution and the loss of wild lands. They have contributed to sprawl (the development of low-density, suburban development). They encourage recreational activities and the rise of fast food and motels. They have even created new types of government regulations and services, including highway systems, safety features, and drivers’ licenses.

The earliest automobiles were powered by steam, electric power, and gasoline. The earliest gas-powered cars were built in 1886, and by 1900 there were several million gasoline-powered cars on the roads of Europe and the United States. Today there are more than 1.4 billion cars in operation worldwide, and about 70 million are built each year. The design of an automobile depends to a large extent on its intended use. For example, automobiles designed for off-road use need durable, simple systems that are resistant to severe overloads and extreme operating conditions. Those designed for high-speed road use require passenger comfort options, optimized handling and stability, and advanced engine performance.

One of the biggest benefits of owning a car is freedom. By driving yourself to work, you can avoid having to depend on others and keep your schedule flexible. By contrast, relying on public transportation can be stressful because of the risk of missing your ride.