An automobile is a four-wheeled motor vehicle that carries one or more passengers and is propelled by an internal combustion engine using a volatile fuel. The automobile revolutionized twentieth-century life, becoming the backbone of a new consumer goods-oriented society and fueling a host of spin-off industries, from steel to rubber to petroleum. Today cars remain one of the main forms of personal transportation, with over three trillion miles (five trillion kilometres) driven each year in the United States alone.
The first cars were built in the late 1800s, but it was Henry Ford who revolutionized automobile production with his mass-production techniques, making the Model T a huge success and reducing the number of car manufacturers to just a few. Other innovations included self-starters, closed all-steel bodies, hydraulic brakes and syncromesh transmissions. After World War II manufacturers concentrated on producing for the war effort and market saturation occurred simultaneously with technological stagnation, so that automobile innovation slowed to a crawl.
A modern automobile has many subsystems with specific design functions. Its interior must provide comfort and safety, while its exterior must be attractive and functional. A cost-efficient manufacturing process is also important, to keep the price of production low. Clear visibility is crucial for safe driving, so the design must include well-placed glass areas. Safety is further enhanced by a sturdy frame and seatbelts. A good automotive design also incorporates a powerful engine that provides excellent performance and can run a long distance between refueling.
