An automobile is a motor vehicle used for passenger transportation. Automobiles are typically powered by an internal combustion engine, fueled most commonly by gasoline (petrol) or other petroleum fuels. Other automotive power sources include diesel, electricity, and hybrids. The automotive industry is one of the world’s largest industries, and automobiles are among the most widespread of modern technologies. In recent decades, many designers have attempted to innovate automobile design, in order to satisfy consumer demands and improve efficiency and safety. Automobiles have become a mainstay of everyday life, with an estimated 1.4 billion in operation worldwide. They drive more than three trillion miles (five trillion kilometres) each year, and are the primary means of transport for most families in the developed world.

Karl Benz is widely credited with inventing the modern automobile in 1885. His Benz Patent-Motorwagen had a two-stroke, gasoline-fueled internal combustion engine and was the first automobile to be produced in large numbers.

Throughout the 1920s, the automobile became a force for change in twentieth-century American society. The industry grew to be the backbone of a new consumer goods-oriented economy, and ranked first in value of production, providing one of every six jobs in America. The automobile also transformed the landscape of urban living, fostering suburbs and expanding cities into rural areas. In addition, the vehicle brought consumers closer to the remote natural world than any other means of transportation had before, influencing architecture and a broader perspective on nature.

In the United States, automobile demand was stimulated by a larger land mass with greater population density, higher per capita incomes, and the absence of tariff barriers to interstate commerce. The nation’s manufacturing tradition and cheap raw materials encouraged mass production, which reduced costs to an unprecedented selling price.

By 1913, the Model T runabout had become affordable for middle-class Americans. Innovating mass production techniques at his Highland Park, Michigan, plant, Henry Ford produced more than fifteen million vehicles of the Model T design, lowering prices even further. This democratization of the automobile enabled automobile owners to explore distant locales, and the car facilitated social interactions that had never been possible before.

Automobiles have also been a driving force in the development of the highway system, and contributed to the proliferation of fast-food restaurants and drive-in movies. They are also a major source of pollution, and their use has prompted efforts to make them more fuel efficient.

Automobile accidents are common, and result in injuries and death to drivers and passengers. Accident prevention is important, and safety features are becoming more sophisticated, as a consequence of the increasing availability of advanced technology in automobiles. Some of these advanced safety features are inbuilt into the design of the vehicle itself, and others are provided by third-party manufacturers as optional extras. The safety features are designed to reduce the risk of injury or death to occupants, as well as to minimize damage to property and the environment. In recent years, the number of automobile accidents has declined, partly due to improved safety features and a rise in awareness of traffic laws by motorists.