The "poor man's" method of transportation in the states is by bus. Grayhound Lines, usually. This was how I sometimes traveled when I was still a student in college. It's usually cheaper than renting a car, but it's not the most comfortable way to travel.

Also, though a few of our major cities (New York, Chicago, San Francisco) have subways, most cities rely on buses for public transportation. At my last job in Spokane, I rode a city bus to work every day.

Greyhound Lines - Wikipedia, the free encyclopedia