The automobile is a self-propelled, four-wheeled vehicle designed to transport two to six passengers and a limited amount of cargo. Automobiles are built for driving on roads and highways and are a primary mode of transportation in most countries. There are an estimated 1.4 billion cars in operation worldwide.
The scientific and technical building blocks of the automobile go back several hundred years. The first true car was a steam-powered vehicle developed by Nicolas-Joseph Cugnot of France in 1769. Other manufacturers produced steam-powered cars until the early 1900s. However, steam engines were heavy, required water to be heated and had a short range before needing to be recharged. By the end of the 19th century, manufacturers had begun to produce vehicles powered by gasoline-powered engines. These were lighter and faster than steam-powered vehicles but had the disadvantage of requiring gasoline, which was not readily available in many places at the time.
By the 1910s and 1920s, Ford was producing automobiles at a rate of 15 million per year using modern mass production techniques pioneered at his Highland Park plant. This revolutionized the way people got around and opened up a world of possibilities for those who could afford to have them. People no longer had to rely on public transportation and could travel long distances with ease. This also allowed women to drive and become more independent of men.
Automobiles have become essential for most Americans, allowing them to travel quickly and easily to work, school, shopping, recreational activities and visits with friends and family. With over three trillion miles (five trillion kilometers) being traveled in the United States each year, automobiles are the main form of personal transportation for most people.
Cars can be divided into different categories according to their intended use and the design of the engine, chassis, suspension and other systems that make them work. Automobiles used on unpaved roads, such as those found in rural areas, need to be rugged and simple, with a high resistance to severe overloads and extreme operating conditions. Vehicles that are used on fast, restricted-access roads require improved passenger comfort options, higher power levels and optimized high-speed handling.
Another important consideration is the appearance of an automobile, including its shape and color. The overall look of the car is determined by the body, which includes the front and rear bumpers, spoilers, side skirts, engine grille and hood, storage trunk and all windows. The shape of the body helps determine the vehicle’s aerodynamics and is important for its safety and aesthetic appeal.
Other features of an automobile include a dashboard with controls for the engine and other systems, a steering wheel, tires, wheels and axles, brakes and a muffler. Some automobiles have additional controls, such as the air conditioning system and audio equipment. In addition, a variety of gadgets and features have been installed to help improve the driving experience for drivers and passengers, such as airbags, traction control and parking assist systems.