Congress should consider increasing the federal tax on gasoline to provide more money for roads, bridges, and public transit, U.S. Sen. Robert Casey (D., Pa.) said Monday.

The current tax is 18.4 cents per gallon and was last raised in 1993.

"I would not rule that out," Casey said of a tax increase, saying it was part of "a whole menu of options" that Congress should weigh as it prepares a new transportation-funding law.

The current 27-month transportation-funding law will expire at the end of September 2014, and Casey held a news conference at 30th Street Station to urge Congress to plan now for a long-term funding plan.

Casey, flanked by SEPTA general manager Joseph Casey and Montgomery County Commissioner Josh Shapiro, said transit agencies and local transportation planners need to know how much money to expect and when to expect it.

"Careening from one short-term transportation bill to another has increased uncertainty for agencies like SEPTA," Casey said. "Congress should begin work now on a long-term transportation bill that allows public agencies to plan into the future."

SEPTA faces a funding crisis that prompted it last week to unveil a doomsday plan for slashing service if the legislature does not come up with more money for public transit.

Most of SEPTA's subsidy for operating costs comes from the state ($595 million this year), while most of its capital funding, for such things as new vehicles and bridge replacement, comes from the federal government ($187 million this year).

"As transit agencies face shrinking contributions from states and municipalities, we need to provide consistent funding," Casey said in a letter Monday to House and Senate leaders. "Failure to do so could result in cuts to routes that commuters depend upon and, ultimately, job losses."

Casey wrote that without more money, the Highway Trust Fund, which pays for roads, bridges and mass transit, "will become insolvent by 2015," costing Pennsylvania tens of thousands of jobs.

Since 2008, Congress has kept the highway fund solvent by transferring $41 billion from the general fund. An additional $12.6 billion is scheduled to be transferred from the general fund next year.

Despite those transfers, the fund is expected to be $15 billion in the red by 2015.

It would take spending cuts of about $51 billion or a gas tax increase of about 10 cents a gallon to deal with the projected shortfalls.

In addition to the federal gas tax, states levy their own taxes on gasoline.

The Pennsylvania tax is 31.2 cents a gallon (32.3 cents if you count the 1.1 cent-per-gallon underground storage tank fee, which the state Revenue Department doesn't but the American Petroleum Institute does). It last went up in 1997.

In New Jersey, the tax is 14.5 cents a gallon (including the four-cents-per-gallon "petroleum products gross receipts tax"). It hasn't been raised since 1988.