The typical American driver could save $1,800 a year by giving up his or her car and taking the train or bus to work.
But there is no such mass transit option for many people.
Such systems only make sense in dense urban areas and, even then, they are often heavily subsidized and only replace the car for some.
Rick Remington, a transportation researcher at Rutgers University in New Jersey, said that a public transit system has to be near cities in order to work.
"It's got to be frequent service, it's got to be convenient, it's got to be fast and it's got to have the population density to support it," he said.
High gas prices are drawing a record number of travelers to public transit systems. But this is just the latest spike in a decade-long rebound of buses, subways and trains, Remington said.
"This isn't just something that arrived with high gas prices," he said. "It's been going on since by the mid-90s. A lot of it was being driven by congestion."
Basically, Remington said, people were fed up. They realized they were losing a good part of their day just sitting in traffic.
LeeAnne Hays, who lives in suburban Kansas outside Kansas City, is one of the new converts to public transit.
She used to drive 17 miles each way, each day to her job, taking the bus on occasion. But as gas prices started to climb, she decided it was time to make a full-time switch.
Hays now drives three miles to the nearest bus stop and takes the bus the rest of the way. It only saves her about $7 a week on gas — not including wear and tear on her car — but she doesn't have to personally deal with traffic.
"Usually, I rest, or read or do something much more pleasant than fighting traffic," Hays said. "For me, I really believe it's a lifestyle change. I detest traffic."
Hays is not a morning person and it takes some self-discipline to get to the bus stop on time. But, she said, "frankly, it has been a fairly painless transition."
Even if gas prices retreat — which Hays believes in unlikely — she will still ride the bus.
"People are still making fun of me in the office for taking the bus, but I don't care," she said. "I'm trying to convince them I'm the hip one."
There are more than 10 billion trips taken on public transit in this country each year, according to American Public Transportation Association, the industry's lobbying and trade group.
While that might seem like a lot, there were 23.4 billion trips back in 1947.
But that all started to change after World War II.
"That's when people left the cities for the Levittowns, the suburban growth which is more dispersed and is auto-centric," Remington said. "The development was based on cheap gas and an automobile society."
Ridership hit a low of 6.5 billion trips in 1972.
"That is now boomeranging," he said. "Gas isn't cheap anymore and the housing markets that are most hurt are those furthest from employment centers. The further you are from your job, the harder it is to sell your house."
Most public transit riders in America still take buses, which account for 60 percent of all rides. Buses use existing roads but also face the pitfalls of traffic. The big recent growth in transit has come from light rail systems, which are cheaper to build than traditional trains and can access smaller markets.