Final answer:
Urban sprawl refers to the geographic expansion of cities into rural areas, characterized by increased traffic, longer commutes, and greater environmental impacts.
Step-by-step explanation:
When automobiles and expressways became widely available, U.S. cities underwent geographic expansion as the friction of distance was reduced. This is an example of Urban sprawl. Urban sprawl involves the spreading out of a city and its suburbs over more and more rural land at the outskirts of an urban area. It often results in increased traffic congestion and longer commuting times as new suburbs are developed farther from city centers. Additionally, it can lead to increased natural resource use and higher pollution levels.