Automobiles (also known as cars or automobile) are motor vehicles that transport passengers and cargo. Most automobiles run primarily on roads, have four wheels, and seat one to eight people. They are powered by internal combustion engines, most commonly gasoline. Invented in the late 1800s, automobiles revolutionized modern life and created an entirely new social order. During the 1920s, they became the backbone of a consumer goods-oriented society and the largest user of steel and petroleum. During World War II, automobile manufacturers funneled their resources into military production. After the war, American production declined while Japanese and European manufacturers took advantage of a growing global market.

The automobile symbolizes both the promise and the pitfalls of modernity. In many ways, it was the most important invention of the 20th century. As the automobile dominated the world’s roadways, Americans began to abandon urban centers in favor of suburban living. Families moved away from town and village, building sprawling neighborhoods with homes surrounded by green grass lawns. The automobile was also a catalyst for the development of a new culture that celebrated individual freedom of movement and action, often without clearly defined responsibilities.

Today, automobiles continue to shape the way we live. They enable us to visit distant places quickly and efficiently. However, when the number of automobiles exceeds the ability of road networks to accommodate them, they can become a major source of congestion and air pollution. They also cause climate change by burning fossil fuels that release carbon dioxide and other greenhouse gases. Fortunately, there are ways to limit the harm of automobiles: by using an environmentally friendly car or walking or riding a bicycle.