Few inventions have had such a strong influence on human life and society in modern times as automobiles. In its broadest sense, the term “automobile” refers to any self-propelled vehicle that is used for transportation over a distance. The vast majority of automobiles are four-wheeled vehicles that are designed to carry a small amount of cargo and to operate on roads and highways. The design of an automobile requires a complex interplay between engineering and aesthetic considerations. Modern automobiles must satisfy standards governing size, weight, and aerodynamics or ways to reduce the friction of airflow over the body, as well as safety features, such as seat belts and steering systems. Thousands of individual parts make up the modern automobile, and they are arranged into semi-independent systems. The engine, the heart of any car, is powered by a system analogous to the human circulatory system that provides coolant fluid and lubrication. The automobile also has an electrical system for powering lights and accessories, and a chassis that supports the engine, braking system, wheels, and tires.

The modern automobile has evolved through a series of innovations, starting in the 1860s with Siegfried Marcus, who built the world’s first internal combustion gasoline motor. This allowed the automobile to achieve high speeds, but it had limited range and was difficult to start. By 1900, three major types of automobiles competed for market share: steam cars, electric cars, and gasoline-powered ones. The gasoline engine ultimately won out.

Automobiles revolutionized society by enabling people to travel long distances quickly and easily. Having an automobile opened up new opportunities for employment and leisure activities. It allowed families to live in different areas and still stay together, and it encouraged sprawl (sprawling low-density urban development). However, the automobile also caused pollution that is blamed for climate change. Automobiles also contribute to traffic congestion, and their crash rates are high enough to cause significant injuries to people.

Many cities have restructured their economies around the automobile, creating jobs and businesses that rely on traffic flow. There are many efforts to make automobiles safer and more environmentally friendly, including research on semiautonomous or autonomous vehicles in which a computerized driving system aids or completely replaces the human driver. Some of these efforts may be successful in the future, although it will likely take a considerable time before they are available to most people. In the meantime, there are a number of options for transportation that can get people where they need to go more efficiently than an automobile. Buses, trains, and subways can travel more quickly than automobiles in congested areas, and they can avoid the problems that can arise when too many automobiles try to move in the same direction at the same time. They are also cheaper than owning and operating an automobile. Taking advantage of these alternatives can save time and money while improving quality of life.