For people like Tammy Walls, a Dallas-area commuter, the Dallas Area Rapid Transit System (DART) is an indispensable necessity.

"It is a lot better than dealing with the traffic and it is a lot less expensive," she says. For Tammy, it is all about the convenience: The ease of taking a system that connects Dallas and 12 adjoining cities with what the agency says is "a modern lineup of public transit services and customer facilities tailored to make your trip fast, comfortable and economical."

DART’s growth and success was an anomaly just 10 years ago. The U.S. has historically lagged behind other countries in Europe and Asia, which urbanized their centers of commerce before the age of automobiles. Americans, on the other hand, grew up with gas-guzzling Chevy V8’s, fins and all, cruising the open roads and going to drive-ins.

While there is a sense that America might still be experiencing growing pains, the pervasive impression of impermanence is now slowly disappearing.

This revolution started in the mid- to late-1990’s, with a vast shift in cosmopolitan life. From Atlanta to New York, people began repopulating once vacant city centers, dispensing with their cars, and embracing a plebeian declaration of environmental awareness.

Today, mass transportation systems in cities like Chicago and Dallas are meeting strong new demand. Public transportation use across the country grew four times faster than the population last year, outpacing the growth in the number of drivers from the first time since World War II.

Dallas’s DART is one such system. The system has been a success ever since voters there gave it the go-ahead back in 1983. Today there is so much demand for mass transit that the city is spending $1 billion on new rails, and that’s in addition to the $2.9 billion they had already earmarked for expansion.

"We can't build it fast enough," says Roger Snoble, the Executive Director of DART. "The original system was only 20 miles long. We're building 24 additional miles just to keep up with the demand."

Experts point to gas prices as one reason people are heading to the rails and taking to the buses. Many remember the oil crisis of the 1970s, which was a warning shot for the sense of entitlement American drivers had enjoyed for so long. People soon realized they were entering a brand new age - an age when prudence would reign over profligacy.

Washington, D.C. is another city that has embraced public transport. Statistics show transit ridership in the nation’s capital grew by 13.2 percent last year - four times the national average.

Even in car-dependent, smog-laden Los Angeles, transit officials are increasing bus service to meet record demand. Earlier this year, the Metropolitan Transportation Authority unveiled a proposed $2.7 billion budget - giving riders more options to relieve the nation's worst traffic congestion.

But even as eager commuters wait for public transport expansion, some are just not willing to do away with their personal space, choosing instead to stay away from the turnstiles.

"Just the freedom and flexibility to come and go when I want to, that’s the asset of having a car," Dallas resident Mark Blenden says.

And there are millions of commuters like Blenden. Collectively, American drivers logged 2.7 trillion miles in their cars last year - enough to drive round trip to the sun 29,000 times.

"When you're in your car, you're in your own space and for more and more of us in busy lives the space in your car may be the only private space you get all day," says C. Van Tune, the Editor-in-Chief of Motor Trend Magazine.

If Tune is right, and the U.S. obsession with the car continues, Americans better be prepared to sit put, and be patient.

With traffic snarling the highways, construction a necessary evil and projects like Boston’s Big Dig turning downtowns into mazes of steel and concrete, Americans can look forward to listening to the traffic report, instead of their favorite CDs.