Virginia finalized agreements Tuesday with CSX, Amtrak and Virginia Railway Express as part of the state’s $3.7 billion passenger rail expansion program that seeks to relieve a rail bottleneck and get more commuters onto trains.

The signing of agreements advances a pledge Gov. Ralph Northam (D) made in December 2019 to significantly grow passenger rail service this decade by building a new rail bridge over the Potomac River, adding new track in the Washington-Richmond corridor and buying hundreds of miles of passenger right of way from CSX.

Within the next month the state will begin taking over some CSX tracks and will start construction of a fourth track in the Interstate 95 corridor in Alexandria this year, officials said.

“This transformative plan will make travel faster and safer. It will make it easier to move up and down the East Coast, and it will connect urban and rural Virginia,” Northam said during a Tuesday announcement in Alexandria. “This historic initiative will help get people and goods where they need to go more efficiently, reduce congestion and pollution, and create a more inclusive economy.”

Virginia and the two passenger railroads have made financial and service commitments that would transform the state’s rail infrastructure over the next decade. Amtrak will contribute $944 million toward improvements and has committed to operating in the state for at least 30 years.

The coronavirus pandemic threatened to delay the plan — which observers and railroad officials say will turn Virginia into a model for intercity train service — but it has stayed on schedule, officials said. Recent progress includes completion of environmental studies for the construction of a new rail bridge connecting Arlington and the District, congressional approval for conveyance of National Park Service land to Virginia and the District for the new bridge, and creation of a new rail authority that is overseeing the program.

“Living through this extraordinary year, everyone stayed at the table, everyone was committed to seeing this through,” Virginia Transportation Secretary Shannon Valentine said.

The state is pursuing a $1.9 billion rail bridge over the Potomac to expand capacity for passenger trains. The new span will run parallel to the existing two-track Long Bridge, the 116-year-old structure owned by CSX that carries all Amtrak, VRE and freight trains between the District and Virginia.

The project’s federal environmental studies were completed in September, opening the door for the final design, financing and construction. It will be at least two years before construction begins, but the new Long Bridge should be operating by 2030, officials said.

Virginia’s rail program is a key piece of a regional plan that envisions a network of high-frequency, all-day commuter and intercity train service that spans from Baltimore to Richmond. Although demand for service is sluggish amid the pandemic, officials say they expect ridership will pick up later this year as more Americans get vaccinated and resume travel.

In the long run, Amtrak expects to add six daily round trips to Richmond. It expects to add a new trip from Washington to Norfolk and another to Roanoke this year. Two more trains would be added — one ending in Richmond and the other in Newport News — by 2026, and three additional to Richmond would be added by the end of the decade. Amtrak now runs five daily Northeast Regional trains to Richmond.

Environmental and rail advocates say the plan will transform rail transportation in the Washington region. It addresses a choke point in the region’s rail system and creates a path toward separating passenger and freight trains to improve efficiency.

“This deal is a game-changer for Virginia,” said Danny Plaugher, executive director of Virginians for High Speed Rail, a nonprofit advocacy group, adding that by 2030 the rail improvements will help move nearly 9 million passenger trips and generate $1.2 billion in economic benefits each year for the state.

Under the plan, Virginia Railways Express will add one trip on each of its two lines this year.

VRE, which carries commuters from Northern Virginia to downtown Washington, has agreed to contribute $200 million to the project over the next decade. The agency said contributions, however, will be well over $1 billion, considering more than $800 million in improvements spelled out in VRE’s six-year capital program.

“These are exciting times for commuter rail in Virginia,” VRE chief executive Rich Dalton said Tuesday.

U.S. Transportation Secretary Pete Buttigieg joined Virginia and railroad officials to mark the event at Alexandria’s Amtrak and VRE station. He praised the collaboration among federal, state and private-sector officials to carry out the 10-year program.

“This is exactly what our country needs more of and exactly what our communities deserve,” Buttigieg said. “The project we’re celebrating today will help people across the region, and the work we’re doing collectively will help people across the country.”

Buttigieg said the nation is ready to support transit, including passenger rail, as it pulls out of a pandemic-fueled economic downturn. He cited the recently approved stimulus package that gives Amtrak $1.7 billion to restore some service and bring back furloughed workers.

“This is just the beginning of what’s possible in transportation infrastructure in this country,” Buttigieg said.

The program will be paid for with local, state and federal money, which includes Amtrak’s financial commitment. Virginia will use some dedicated state rail funds and also seek other money, including vying for a piece of President Biden’s $2.25 trillion infrastructure package.

As part of the deal, Virginia is purchasing 223 miles of track and more than 350 miles of railroad right of way from CSX for $525 million, including half the right of way between Washington and Richmond. The transaction will be completed in three phases, with all transfer of tracks to be completed next year.

The investments will result in a dedicated passenger rail corridor between Franconia and the District, allowing for more trains. The project also will expand a vital link in the national rail network by connecting the northeast and southeast corridors.

VRE’s Fredericksburg Line, which uses the CSX tracks, will see an increase in service of 75 percent during peak periods by the plan’s completion in 2030. The line, which operates eight round-trip trains each weekday, will add six new round-trip trains. One is planned for this year.

Virginia officials are still negotiating with Norfolk Southern to allow expansion on VRE’s Manassas Line, which has eight daily trips. The plan calls for one new trip this year and three new round trips by 2026.

The agreement, officials said, will allow VRE to add special Friday evening trains to give Virginians the option to use VRE after normal commuting hours. VRE also plans to introduce weekend service.

Outside the Washington region, Virginia will acquire from CSX the 186 miles of track on the Buckingham Branch Line, between Doswell and Clifton Forge, which will allow Virginia to launch an east-west train route from Norfolk to the Roanoke area.

The state also will acquire the rights to use the abandoned S-Line from Petersburg to Ridgeway, N.C., which could facilitate plans for a high-speed train system in the southeast.

“It will be easier to hop on Amtrak to New York for the weekend,” Northam said Tuesday. “It will be easier to commute to work using VRE, and it will be easier to take a train from southwest Virginia to Northern Virginia.”