Automobiles are self-propelled vehicles that carry people and goods over long distances. The automobile industry includes all activities associated with design, production, marketing, and distribution of passenger cars and trucks. Since the 1920s, automobiles have generally been mass-produced to meet consumer demand. To increase sales and profits, manufacturers frequently make changes to automobiles, such as engine performance and suspension. Many of these innovations have been designed to improve safety, comfort, and convenience.
The scientific and technical building blocks of the modern automobile go back several hundred years. The French engineer Joseph Cugnot built the first self-propelled vehicle in 1789, a steam-driven carriage. By the late 1800s, steam-powered cars could reach speeds of up to 3 mph (5 kph). Battery-powered electric cars had a 38 percent share of the United States market in 1900, but they were slow, expensive to operate, and needed frequent recharging.
Karl Benz developed the first practical gasoline-powered automobile in 1885, a prototype called the Benz Patent-Motorwagen. It used a two-stroke internal combustion engine that sent chemical energy through a piston to power the wheels and propel the vehicle forward. By 1888, Benz had improved the engine to four strokes and introduced his four-wheeled Model T automobile.
Today, the automobile is a primary means of transportation for most Americans. Depending on their lifestyle and needs, consumers can choose from hundreds of different models manufactured by domestic and foreign companies. The automobile has also become a symbol of American freedom and wealth. In addition, it provides an important link to work, school, social events, and family life.
In the early 21st century, there has been a renewed focus on developing a practical automobile in which a computerized driving system greatly aids or replaces human drivers. This effort has been accelerated by the proliferation of personal digital assistants (PDA), such as the Apple iPhone and the Google Android phone, which allow drivers to use voice commands and touchscreen displays while operating their car. Several companies are developing software to enable PDAs to control all of the car’s systems, including navigation, communications, and security.
The safety features of an automobile include seat belts, air bags, and stability control. There are also devices that monitor the driver’s behavior and can detect if the vehicle is going off course or colliding with another vehicle. Some automobiles also have a collision warning system that will sound the horn and activate the headlights when a potential collision is detected. Some models are being built that can even stop the car if it gets too close to another vehicle or an object. A similar technology has been integrated into commercial airplanes to prevent collisions and reduce pilot fatigue.