Automobiles are wheeled vehicles used for transporting people. They can be powered by either an internal combustion engine or an electric motor. The branches of engineering that deal with automobiles are called automotive engineering. Today there are 1.4 billion cars in operation around the world and 140 million in the United States alone. Automobiles play a significant role in our everyday lives. Without them, we would be unable to work, run errands, or see family and friends.
The scientific and technological building blocks of the automobile date back several hundred years. The first self propelled road vehicle was a steam powered car built by Nicolas Cugnot in 1769. Samuel Brown invented the first gasoline powered car in 1826. Karl Benz of Germany improved the engine and chassis of his Benz Patent-Motorwagen in 1885. He introduced an accelerator for speed regulation, a spark plug, and a battery ignition system.
In the 1920s Henry Ford innovated mass production techniques and the Big Three automakers emerged: General Motors, Ford, and Chrysler. Until the 1930s automobile design was largely dictated by marketing and economics rather than engineering.
Today, most new cars are sold in a variety of styles and sizes, from sporty coupes to spacious sedans. Many are equipped with advanced safety features such as tire pressure monitoring systems, traction control, and electronic stability control. These safety features are becoming mandatory on most new cars as consumer demand and government regulations increase. Passenger vehicles make up the majority of the 1.4 billion cars in operation, and some 70 million are built each year worldwide.