Gas prices could boost demand for transit cards.

The steep rise in gas prices has squeezed workers and may force more of them to use public transportation.

Transit benefits vendors say demand for their services is growing.

"We are seeing ongoing demand for transit cards. I think it will continue to rise as gas prices go up even more," says Tom Guiler, vice president of Benefit Resource Inc., which offers eTRAC debit cards that allow users to pay for transit and parking expenses. "Right now, we have a couple thousand employees enrolling a month," he says.

In April, wholesale gasoline prices hit 2