Automobiles are four-wheeled vehicles that transport people and goods. They are the most important means of transportation worldwide, with over three trillion miles (five trillion kilometres) traveled each year. Automobiles are used in a wide variety of ways, from local trips to work or school to long distance journeys to visit friends or family. As a result, automobile design must be tailored to suit the intended use, with products for off-road conditions needing durable and simple systems while those for high speed or limited-access roads must have advanced features and optimized passenger comfort options as well as improved engine performance and vehicle stability.
The development of the automobile began with a number of scientific and technical firsts, starting in the late 1600s when Dutch scientist Christiaan Huygens invented a type of internal combustion engine sparked by gunpowder. In the 1800s a number of manufacturers developed cars powered by steam, electric power, and gasoline. Steam cars moved slowly, while electric cars needed to be recharged every 50 miles (80 kilometers). Gasoline-powered engines were more reliable and could reach higher speeds than steam or electric models.
A major change in the automobile came about in the early 1900s when Henry Ford introduced his assembly line. This allowed car factories to produce large numbers of automobiles quickly. It also meant that more people could afford to own a car. This allowed them more freedom and the ability to travel for pleasure.
After World War I (1914-18), cars became more streamlined and comfortable. Steel bodies replaced wooden ones, and heaters and air conditioning were added to make driving more pleasant. In addition, safety features like seat belts and highway rules were created.
As the demand for automobiles continued to increase, industries and jobs grew to supply them. Those included oil and gasoline producers, rubber suppliers, tire manufacturers, and parts makers. Services such as gas stations and convenience stores sprang up as well. People gained more freedom to move about and did things such as go to amusement parks, restaurants, and shop. They also began to vote, which was a new right for women in America.
Although a few people may claim to have invented the automobile, history credits Karl Benz, a German engineer, with the first true motor car. Other inventors and engineers worked to improve on these designs, including those who designed the first successful steam, electric, and gasoline-powered cars.