The federal government is awarding the state $372 million for the replacement of the Sagamore Bridge, a crucial first step towards paying for the multibillion-dollar project that would erect new crossings onto Cape Cod. 

Massachusetts lawmakers announced the grant from the U.S. Department of Transportation Friday evening, and said it could be a sign of further funding for the Bourne and Sagamore bridges, the two aging roadways that serve as the only vehicle passage to and from the Cape.

“This funding is a critical down payment on the effort to replace the Sagamore and Bourne bridges and a recognition that replacing the aging bridges will bring immense economic, environmental and social benefits to Cape Cod, the Islands and the entire Commonwealth,” U.S. Rep. Bill Keating and U.S. senators Edward Markey and Elizabeth Warren said in a statement Friday. 

Opened in 1935, the two 88-year-old arch bridges are essential access points to the Vineyard. Any freight bound for the Island that originates from off-Cape must go over one of the bridges; Islanders driving to Boston or beyond are bound to cross the deteriorating spans. 

The bridges have both outlived their intended life and in 2019 the U.S. Army Corps of Engineers, the federal agency that owns the bridges, concluded that they should be replaced. Initial estimates to build new bridges and demolish the existing ones were at about $1 billion. 

But the project has struggled to get funding, and since the pandemic the price tag has ballooned to more than $4 billion.

Earlier this year, the state said it would first prioritize replacing the Sagamore Bridge because it sees more traffic annually. 

Gov. Maura Healey’s administration has another application for $1.06 billion to the federal Bridge Investment Program. The governor has also said she hopes to put $700 million in state money towards the bridges, as well as garner $350 million in the federal budget. 

This initial $372 million chunk could act as ballast for more funding, officials said. 

"This award is an important step in the replacement of the Cape Cod bridges, and will support our second highly competitive application for federal funding to move this project forward," Quentin Palfrey, the state’s director of federal funds and infrastructure, said in a statement.

Replacing the bridges is a complicated proposition. The Army Corps has said if the project were to move forward, it would build the new bridges adjacent to the existing ones, necessitating overhauls of the roads leading to the bridges.

The Army Corps and the state have also worked out a deal where the bridges would be turned over to Massachusetts after they are built. 

In their current state, the bridges have had to undergo more frequent and intensive repairs. Work on the Bourne Bridge earlier this year cut the four-lane bridge down to two, 24-hours a day from mid-September to early November. 

If new bridges aren’t built, officials have estimated that the current bridges may need permanent lane closures in the 2030s, potentially leading to long traffic jams that could affect Island life. 

In a letter to Senator Warren from August, the Oak Bluffs select board urged the government to replace the bridges and stressed how reliant the Vineyard is on the struggling infrastructure. 

“[O]ur dependency on the Cape Cod bridges for the movement of people, goods, services and supplies cannot be overstated,” Oak Bluffs town administrator Deborah Potter wrote. “These two access points are the lifelines of our town, connecting us to the essential resources and opportunities we require for sustenance and prosperity.”