Despite a $1.5 billion infusion of transportation money from the federal economic stimulus bill, Pennsylvania faces a looming funding crisis that could set back efforts to rebuild roads, bridges and transit systems.

Disagreements at the federal and state levels over how to fund infrastructure improvements could hit hardest in July 2010 with draconian cuts in allocations for the Pennsylvania Department of Transportation and transit agencies like the Port Authority.

"It's kind of a double whammy that we're facing a year and a half from now," said Rep. Joseph Markosek, D-Monroeville, chairman of the state House Transportation Committee.

Proposed solutions -- higher federal and/or state gasoline taxes, new fees, more highway tolling or more deficit spending -- all are unpalatable.

"We have to get the money from somewhere, or we could sit and wait and watch more bridges fall down," said Jim Berard, communications director for the U.S. House Committee on Transportation and Infrastructure.

Because the federal government hasn't approved the state's application to impose tolls on Interstate 80, a large hole is developing in Act 44, enacted by the Pennsylvania Legislature in 2007 to fund highways and public transit.

Meanwhile, the federal transportation legislation called SAFETEA-LU expires at the end of September, and Congress is scheduled to draft a new multiyear highway and transit funding bill.

There's a large hole there, too -- the Highway Trust Fund is essentially broke, and, without new revenue sources, federal aid for highways, bridges and transit likely would decline.

While the day of reckoning is a ways down the road, local officials are starting to worry.

"We're dealing with a real financial challenge," said Dan Cessna, the PennDOT district executive for Allegheny, Beaver and Lawrence counties.

If I-80 is not tolled and no other funding is substituted, Act 44 funding of highways and transit would drop from $900 million annually to $450 million.

PennDOT statewide will get $300 million less in highway and bridge funding starting on July 1, 2010, and transit agencies would take a $150 million hit.

"Then we are essentially back into the same statewide funding crisis we were in two or three years ago," said Steve Bland, Port Authority chief executive officer.

Mr. Cessna noted that the region's four-year Transportation Improvement Program was written and funded with the assumption that tolls would be imposed on I-80.

The plan has scores of bridge replacement projects for 2010 and 2011 that were to be funded through Act 44, and they could be in doubt if I-80 tolls or a substitute revenue source aren't provided.

That would exacerbate an already difficult situation.

"We're fighting a big backlog of maintenance deficiencies that grew over a number of years, and that's not something you dig your way out of quickly," Mr. Cessna said.

The Pennsylvania Turnpike Commission was rebuffed in September in its application to the Federal Highway Administration for permission to charge tolls on I-80.

The I-80 tolls were to provide about a third of the highway and transit funding generated under Act 44; the remainder is from turnpike tolls.

Joe Brimmeier, chief executive officer for the turnpike commission, said the agency is waiting to resubmit its application to toll I-80. FHWA's senior staff, to be appointed by the Obama administration, is not yet fully in place.

"Once we feel we can get a fair evaluation, we would like to resubmit it. We were directed by Act 44 to do this. Unless somebody changes the law, we have to do it," he said.

U.S. Rep. Glenn Thompson, R-Howard, is trying to change the law. He has introduced a bill, the Keeping America's Freeways Free Act, that would prohibit the tolling of federal highways, including I-80.

Gov. Ed Rendell's alternative to I-80 tolls, a proposal to lease the Pennsylvania Turnpike to a private operator for upfront cash to pay for highways and transit, also is stalled.

Mr. Brimmeier said the state was fortunate that the Rendell plan didn't fly. The governor wanted to lease the turnpike for 75 years to a private firm that would have paid $12.8 billion up front. Nearly a third of that money would have vanished by now in the collapse of the financial markets, Mr. Brimmeier said.

Other federal and state proposals to generate revenue for transportation projects have met resistance.

Two congressional commissions have recommended raising the federal gasoline tax, which has been at 18.4 cents per gallon since 1993 and has lost much of its purchasing power due to inflation.

U.S. Rep. James L. Oberstar, D-Minn., chairman of the House Transportation and Infrastructure Committee, has long supported an increase.

But the new U.S. transportation secretary, Ray LaHood, recently told a House subcommittee that the Obama administration "is not in a mood to raise gasoline taxes with the economy as bad as it is."

Mr. LaHood floated the idea of a fee based on vehicle miles traveled, which is under study in several states and gaining some popularity as a possible alternative to the gasoline tax.

But the White House quickly shot that down, with President Barack Obama's press secretary, Robert Gibbs, saying such a switch "is not and will not be the policy of the Obama administration."

Some have suggested that Congress, fearful of imposing higher taxes or new fees, will instead give states more discretion to impose tolls on interstate highways.

Mr. Brimmeier went so far as to predict that every interstate highway in Pennsylvania would be tolled within the next 10 years.

"Tolling is the wave of the future. There's never going to be enough fuel taxes or registration taxes to meet the needs for transportation infrastructure in this state and this country," he said last week.

Mr. Oberstar, whose committee will draft the new federal transportation bill, opposes tolls on interstate highways built with federal funds.

Mr. Markosek, who said his top priority is getting I-80 tolls approved, said he hopes the Obama administration will be more receptive to the idea.

Even with revenue from I-80, Act 44 falls short of providing the funding levels recommended by the Governor's Transportation Funding and Reform Commission in 2006 to repair aging infrastructure in a state with more than 5,800 structurally deficient bridges.

Craig Shuey, executive director of the state Senate Transportation Committee, said "we need to continue having a strong conversation about what people are willing to accept to provide for a modern, adequate transportation system. It's a very expensive proposition.

"Right now, we do have some breathing room," he said.

Not everyone sees it that way.

"Politically, sitting back doesn't work for a big reason," Mr. Markosek said. "Next year is an election year. Whatever tough votes we need to get, they're going to be more difficult next year when legislators are up for re-election."

"There's not a lot of time," Mr. Bland said. "The clock is ticking."