Automobiles are self-propelled vehicles that run on an internal combustion engine fueled most often by gasoline. They are one of the world’s largest manufacturing industries.
Throughout history, the automobile has evolved from horse-drawn carriages to sophisticated systems that combine fuel efficiency and speed. These systems have changed the way we live, travel, and work.
In the United States, cars are responsible for a significant portion of ground transportation. They account for almost a quarter of all motorized vehicles on the road and for more than three trillion miles (almost five trillion kilometers) of vehicle travel each year, on average.
They play a pivotal role in the development of our cities and in transportation planning, allowing flexible distribution patterns to be created for the transportation of goods and services. In addition, they offer the convenience of quick, long-distance mobility for individuals and families.
Cars are also useful for a wide range of social and cultural activities, such as vacation travel, dining, and shopping. They save people time, facilitate their lives, and provide a sense of independence.
During the first half of the twentieth century, the automobile evolved from a marginal curiosity to the dominant mode of ground transportation in the United States. It spawned a vast network of national interstate highways and spurred the postwar suburban sprawl, opening up unprecedented possibilities of mobility for the average American.
But these advances also produced a host of stubborn social ills: air pollution, traffic jams, road rage, and a major contribution to global climate change. The automobile remained a central element of the American social order through war, prosperity, and depression.
The American automobile industry grew from a small cluster of independents in the early years of the twentieth century to the big three manufacturers of Ford, General Motors, and Chrysler. But the Great Depression, which hit the auto industry hard, shook out many of the smaller firms and created a pattern of oligopoly that lasted into the postwar period.
A car’s body is typically made of steel or aluminum, though fiberglass and plastic are also used. The body is designed to protect passengers from the impact of a crash and to crumple easily, absorbing much of the shock of an accident.
Another important component is the chassis, which supports all of the car’s components. It is also the place where the wheels, suspension, steering, and braking systems are attached to the body.
In addition, the chassis provides a foundation for the car’s engine. It also helps the engine function smoothly and efficiently.
The chassis is also an important part of the engineering and design process, determining everything from the type of material that will be used to build the frame to the type of wheel and tire configurations that will be used on each model. The automobile’s structure is also a significant factor in the cost of production, as it must be strong enough to resist the rigors of driving on the open road and be capable of absorbing the weight of the driver, cargo, and other passengers.