At stake is $1 billion a year in federal funding for Massachusetts transportation projects, accounting for about half the needed money, with the state covering the other half, for several years’ worth of projects.

State political leaders call a pair of approaching transportation deadlines — one to refill the highway trust fund by this summer and another to renew the national transportation program — a “looming crisis.”

WASHINGTON — Nearly $5 billion of proposed road, transit, and bicycling improvements across Massachusetts are at risk because Congress has failed to act at a time when the nation’s main source of highway funding verges on insolvency.


The dozens of projects potentially affected are large and small — ranging in cost from a few hundred thousand dollars to a few hundred million dollars. Among them are the reconstruction of Interstate 91 in Springfield, resurfacing of US Route 1 in Peabody, bridge replacements on Route 16 in Medford and Everett, and a new lane on Route 128 north of Wellesley as part of an ongoing project to expand the entire highway to four full-time lanes in each direction. Other projects include a bicycle shuttle on Cape Cod, a harbor walking path in Dorchester, rotary fixes, and a new pedestrian bridge in Western Massachusetts.

A prolonged funding shortage could also derail the final phase of the Green Line extension in Medford and the planned $1 billion South Station expansion.

“That would be an enormous cut to our pretty ambitious transportation program,” said Richard A. Davey, the state transportation secretary. “Everything I think that the governor has worked so hard for in transportation would be in jeopardy if we don’t see the highway trust fund replenished in some form.”

Massachusetts officials have joined a national chorus of state government, transportation advocacy, and private construction industry voices in urging swifter action from a dilatory Congress.


The most significant deadline could come in July or August, when the trust fund is projected to dry up. The second deadline, to pass legislation renewing spending authority for highway money and most other federal construction projects, comes at the end of September.

Massachusetts officials said they have yet to slow any projects nor has the Patrick administration indicated which projects would be in jeopardy should Congress fail to reach a deal. But they caution that all of the $4.9 billion in projects included on a 70-page list covering four years of plans are in danger.

Davey said he is counting on a last-minute deal based on political pragmatism.

“Tip O’Neill said it best: ‘There’s no such thing as a Democratic or Republican pothole,’ ” Davey said. “These aren’t state employees that will be largely affected. These are private sector construction companies that would be largely hurt.”

Though many in Congress agree that something must be done to plug the large hole in the highway fund, lawmakers have yet to reach consensus on how much to spend, how long to fund it, and where to get the money.

Congress has long relied on the federal 18.4 cent gas tax. But even as cars become more fuel efficient and inflation raises construction prices, the federal gas tax has not gone up since 1993. Attempts to raise it routinely fail.

Instead, the federal government has used more than $50 billion in general fund money since 2008 to plug gaps in the fund. The transportation fund will need another $99.5 billion from the general fund over the next six years to keep funding to the states at current levels while keeping up with inflation, according to the Congressional Budget Office.


That’s because the gas tax is projected to stay relatively flat, generating about $39 billion a year for the next decade. But construction costs, which continue to grow, are expected to exceed collections by at least $15 billion beginning in the 2015 budget year.

It is becoming increasingly difficult to make up for the shortfall with general revenues at a time of growing budget deficits and other competing priorities.

“The hole that has to be plugged gets bigger every time and the ability to find money from the general fund gets harder,” said David Goldberg, spokesman for Transportation For America, a national organization representing local business and civic organizations. “Every time you have a must-do budget move like this, it opens the door for brinkmanship.”

Representative Michael E. Capuano, a Somerville Democrat who serves on the transportation committee, said Congress needs to find a more permanent solution — raising the gas tax, replacing it with a tax on miles traveled by car, or some other source of money. The recent trend of figuring out how to pay for road fixes at the last minute is “silly,” he said.

“You cannot build the same number of roads or fix the same number of bridges with the same number of dollars you had — or fewer dollars — than you had in 1993,” Capuano said.


Last week, President Obama’s administration put forth its first major transportation bill since he took office. The bill would spend $302 billion over four years, relying on a combination of gas tax and closing corporate tax breaks.

It would also allow states to install new tolls on interstate highways, something that is prohibited in all but a few cases, including the Massachusetts Turnpike. The turnpike was built with state money and tolled before it became part of the interstate system.

The toll proposal is a recognition that the federal government cannot keep up with the demand from states for more money.

The Patrick administration has been studying tolling options and welcomed the Obama proposal, which still needs congressional approval. Cyndi Roy Gonzalez, assistant state transportation secretary for communications, said the state’s biggest impediment to adding new tolls has been the federal government, which has allowed a limited number of states to add tolls as part of a pilot project.

But tolling I-93 and other interstates has long been controversial and, given the remaining federal and state political obstacles, it appears unlikely to happen before Patrick’s term expires in January.

Last year’s government shutdown provides a reminder of how difficult it is to reach consensus on spending bills in Congress. The tenor in Washington in the last few weeks has done nothing to dispel concerns that making a bipartisan pact could be difficult, as members of the House and Senate spend most of their time on symbolic votes aimed at scoring political points in this November’s Congressional elections.


Though few lawmakers have come out against transportation funding, the problem is that finding money without raising taxes or enlarging the deficit is proving difficult.

Club for Growth, a political committee influential among conservatives, goes a step further, saying the entire federal program should be shut down. Allowing states to keep their federal gas tax collections would save money on federal overhead and give local officials more autonomy, said Barney Keller, the group’s spokesman.

“Politicians in Washington, when they get their hands on a funding source, they go on spending binges,” Keller said. “It’s a never-ending system that will only be perpetuated unless Congress devolves the highway trust fund to the states.”

The current funding formula is complex, rewarding some states that have lower populations and larger land masses with extra highway money. All states get more money than they put in. Defenders of the current program warn that leaving states on their own could mean even more disparity in road quality from state to state.

A spokesman for House Transportation and Infrastructure Committee chairman Bill Shuster, a Pennsylvania Republican, said he agreed the problem is urgent but did not endorse a specific remedy. House Speaker John A. Boehner, a Republican, said earlier this year that the hunt for money was underway, but he ruled out any “bailout” that depended on using the general fund.

Senator Edward J. Markey, a Massachusetts Democrat who serves on two committees involved in the bill, called the transportation deadlines “the most important priority for Congress this summer” in a statement.

“If we do not address this looming crisis, we will chill long-term investment in construction, neglect Massachusetts roads, bridges, and transit, and undermine our economy and job creation,” he added.

A short-term fix, which many observers predict, could avoid an emergency. For example, lawmakers could try to find a few billion dollars to fund highways projects beyond the November elections by ending an unrelated tax break or dipping into the general fund.

But, state officials warn, that presents its own set of problems, given that many projects take several years to plan and execute.

The Obama administration has said that it would welcome more congressional input, but has been adamant that something be done before the deadlines.

US Transportation Secretary Anthony Foxx recently finished a national bus tour, where he visited manufacturers, bridges, freight facilities, and highway projects to emphasize the need for transportation spending. His office has begun publishing an online “ticker” devoted to updates on the diminishing highway fund.

Noah Bierman can be reached at nbierman@globe.com. Follow him on Twitter @noahbierman.