Automobiles are self-propelled vehicles used for transporting passengers and goods. They are characterized by their power sources, such as internal combustion engines and electric motors.

The invention of automobiles ushered in a new era of freedom and mobility for individuals and created many new industries. The automobile is a complex technical system, composed of thousands of individual parts and systems. These systems are designed to make the car run, keep it safe, and reduce noise and pollution.

A new car generally takes three to five years to develop from initial concept to assembly. During this time, marketing plans and public tastes are considered to guide development of designs that fit a particular market. Computer-aided design equipment is often used to produce basic concept drawings and clay models of a proposed vehicle. Styling engineers review these sketches, and aerodynamic experts study air-flow parameters to predict what the vehicle might do in crash tests.

During the first half of the twentieth century, automobiles transformed American society, spawning national interstate highways and encouraging sprawl (straggling, low-density urban growth). But they also contributed to many social problems, including air pollution and traffic congestion.

In the United States, Henry Ford revolutionized the manufacturing of automobiles with his mass production assembly line. Using this method, Ford and other manufacturers reduced the cost of automobiles while enabling consumers to purchase reliable cars at affordable prices.

Today, the majority of Americans own a car. It is a major part of their lives, and it provides an essential lifeline for their transportation needs.

The automobile evolved from a curiosity to a dominant mode of ground transportation for the general public, transforming cities and towns across the nation while creating an affluent class of industrial workers. But the automobile also promotes sprawl, which degrades landscapes and produces urban congestion.

A major innovation in automobile engineering occurred with the invention of the internal combustion engine, which burns fuel to generate electricity for powering the wheels. The inventor, Siegfried Marcus, began work on a vehicle in Vienna, Austria, in 1870.

He tested a model of his invention in September of that year and put it aside. The engine was patented in 1886 and the first vehicle based on it was built in 1888.

After Benz, several other pioneers in Europe developed automobiles to a stage of commercial feasibility. During this period, automobiles also developed rapidly in other parts of the world.

In the United States, Henry and William Ford conceived of the automobile and started production in 1908. These two men were responsible for the establishment of the mass-production assembly line that made reliable automobiles within the reach of most middle-class Americans.

By the 1920s, Ford’s production methods had been applied to a wide range of other items and had led to a shift in the economic structure of the country from scarcity to affluence. By bringing reliable automobiles to the masses, Ford and other manufacturers helped the United States overcome the effects of the Great Depression.