In the early 1900s streetcars and electric interurban systems helped fill the nation's transportation needs. By 1917 there were 45,000 miles of transit track in the country and millions of streetcar riders. But over the next few decades, the limitations of streetcar systems, government and corporate policies and actions, consumer choice, and the development of alternatives—especially the bus and the car—helped make trolleys obsolete.
Buses started to replace trolleys in the 1910s. Many commuters considered buses a modern, comfortable, even luxurious replacement for rickety, uncomfortable trolleys. Buses made business sense for transit companies; they were more flexible and cheaper to run than streetcars. In a few cities, auto and auto-supply companies, including General Motors, Firestone Tire and Rubber Company, and Standard Oil of California, bought an interest in transit companies and encouraged the conversion from streetcar to bus. But many cities made the choice to switch without this influence, and by 1937, half of the U.S. cities that had public transit were served by buses alone.
Most importantly, Americans chose another alternative: the automobile. Cars became the commuter option of choice for the growing number of people who could afford them. In Washington, D.C., the last streetcar ran in 1962.