The bipartisan infrastructure bill adopted by the House late Friday will almost immediately give transportation agencies in Maryland, Virginia and the District a major boost in funding. The two states will see federal dollars rise by about one-third while D.C.'s allotment will jump by 50 percent in the fiscal year that began last month.

Transportation funding in the package would be worth at least $18 billion to the Washington region over the next five years, according to analysis from the American Road and Transportation Builders Association (ARTBA). It’s unclear how the money will be spent, but transportation agencies are likely to use it to advance existing spending plans and unlock projects that previously were unaffordable.

Among the potential beneficiaries: The District’s Union Station and the Long Bridge across the Potomac River. Other projects that could see a financial windfall include trails in Germantown and new transit connections such as a bus rapid transit line in Fairfax County.

Gregory Slater, Maryland’s transportation secretary, said his department would work with local communities to figure out where to best spend the money with a focus on keeping existing networks in good shape.

“As we address the large backlog of system preservation and capital needs across all modes of transportation, we will be looking to improve safety and accessibility for all users, and deliver smart infrastructure that incorporates technology, flexibility and future growth,” Slater said in an email.

Michael Sakata, president and chief executive of trade group Maryland Transportation Builders & Materials Association, said smaller jobs like repaving roads will get moving first before state and local governments start turning to bigger projects already on their shelves.

“They’ll dust off those plans and go right to them,” Sakata said. “We have not seen this type of investment in forever, let’s be honest.”

The ARTBA analysis found Maryland received $918 million in federal road and transit funding for the budget year that ended Sept. 30. That total is expected to jump to $1.2 billion because of new money in the infrastructure bill. Virginia’s transportation-related funding will jump from $1.3 billion to $1.7 billion. In the District, federal aid will grow from $374 million to $560 million. The bill also provides for Metro to receive $150 million annually through 2030.

Federal transportation money is generally passed on to states and transit agencies, which have considerable latitude over how it is spent. Much of the spending is likely to be shaped by elected leaders, as local officials envision the future of their transportation networks at a time when the pandemic has scrambled how people get around.

The first round of that debate played out in Congress, where some Democrats pushed unsuccessfully for limits on highway construction and a bigger boost in transit funding. The bill that emerged from bipartisan negotiations in the Senate retains the federal government’s focus on highways, but much about how the package will be put to use is undecided.

Marshall Herman, a spokeswoman for the Virginia Department of Transportation, said it will be up to federal officials to issue guidelines about the new money before the agency can make final determinations about how it will be used. The D.C. Transportation Department didn’t respond to questions about how additional infrastructure money will be used.

Some local leaders might seek wider roads while others could seize on parts of the bill that seek to improve safety for pedestrians and cyclists, or overhaul transit systems.

In Maryland, where Gov. Larry Hogan (R) is term-limited, his successor could seek to revive the Red Line light-rail project he canceled in Baltimore. Transportation was not a major issue in Virginia’s gubernatorial race, but Gov.-elect Glenn Youngkin’s campaign has indicated he would seek to invest more in roads and highways.

Sen. Mark R. Warner (D-Va.), part of the bipartisan group that hammered out the $1.2 trillion package, said he expected to see new investments in the Mayo Bridge in Richmond and Interstate 81 in western Virginia.

“This historic funding will be accessible by way of competitive grants, as well as through local governments, who will have a lot of say in distributing dollars since they know their communities best,” Warner said.

Sen. Ben Cardin (D-Md.), chairman of the Senate Environment and Public Works subcommittee on transportation, has said the bill will help advance bridge projects along Interstate 95 near Baltimore and upgrades to rural highways. Funding from a $7.2 billion Transportation Alternatives Program could be used to guarantee safe pedestrian and bike access to Purple Line stations in Montgomery and Prince George’s counties, his office said.

Amtrak emerged as a winner in negotiations, with the package including $66 billion for rail — a significant expansion in federal support. Cardin’s office said the money could be used to replace the Baltimore and Potomac Tunnel — a Civil War-era bottleneck in the Northeast Corridor’s rail network — and to rehabilitate rail stations in Baltimore and Washington. Amtrak says it also will use the money to replace 45-year-old train sets.

“This bill will allow Amtrak to advance significant infrastructure and major station projects on the [Northeast Corridor], purchase new passenger rail equipment and develop new rail corridors, bringing passenger rail to more people across the nation,” Amtrak chief executive Bill Flynn said in a statement after the vote.

Rep. Gerald E. Connolly (D-Va.) said federal coronavirus relief money had prevented Metro from having to take draconian measures to address its looming budget shortfall last year. But he said funds in the infrastructure bill will help the agency regain its footing as it climbs out of the pandemic amid a steep drop in ridership.

The infrastructure package includes Connolly’s legislation, the Metro Accountability and Investment Act, which extends long-term funding for Metro, provides operating subsidies from the federal government for the first time and offers conditional bonus funding if the agency undertakes certain oversight measures, such as strengthening its inspector general’s office.

“We’re buying time here and making repairs to the system in the expectation that, when the pandemic is over, ridership will rebound, and Metro will be in a better place when that happens because we’ve used this time to make investments that have been languishing,” Connolly said.

Rep. Anthony G. Brown (D-Md.) said a provision intended to reconnect communities divided by highway projects — often disproportionately affecting minority neighborhoods — will be significant for Baltimore, where an infamous Highway to Nowhere divides West Baltimore.

The city and communities across the nation that have been hurt by discriminatory investments can use the money to retrofit spaces to create parks and green space — or dismantle those earlier projects, Brown said. How they use the money would be up to them, not the federal government, which he said often made the discriminatory investment in the first place.

“This is going to be very important as we look to reconnect communities,” Brown said. “The most important role I can play is provide federal funds and empower communities and local governments to put that to the best use for the community.”

President Biden has touted the job-creating potential of the new spending, which economists say will put hundreds of thousands of people to work. The infrastructure building firms that Sakata’s group represents are eagerly awaiting the new money, he said, preparing to hire employees and bid on work.

“Our industry needs it,” he said.

Luz Lazo contributed to this report.