Automobiles are wheeled vehicles that have an internal combustion engine or electric motor and are used for transportation. Automobiles are usually equipped with four to eight wheels and are able to carry a passenger and cargo. The branches of engineering that study the manufacture and technology of automobiles are known as Automotive Engineering.
One of the most significant inventions in modern history, the automobile accelerated economic growth and connected people like never before. It ushered in leisure activities such as travel and recreation, and provided new services such as hotels and restaurants. At the same time, it caused problems such as air pollution and traffic congestion, and led to the need for new laws governing road use.
In a relatively short period of time, the automobile became the primary mode of family transportation in most parts of the world. Today, there are more than 70 million passenger cars on the roads worldwide. The United States has more passenger cars than any other country. Each year, Americans drive three trillion miles (five trillion kilometres) in their cars.
Almost as long as there have been automobiles, there have been automobile accidents. The first documented car accident occurred when Joseph Cugnot crashed his steam-powered vehicle into a wall in 1771. In the 19th century, Karl Benz invented a gas-powered car with an internal combustion engine and started producing them in 1886.
Over the decades, hundreds of inventors worked to improve and refine the automobile. As a result, the car that you drive on the highway or around town is far more advanced than the one that was designed in the 1930s. Current models are lighter, more fuel-efficient, more powerful, handle better, keep their occupants safer, and can do things such as accelerate to 60 mph in just 3.1 seconds.