Gov. Ralph Northam announced Friday that Virginia has selected a contractor to build two new tunnels and widen a major highway in Hampton Roads. The $3.3 billion price tag — funded by regional gas and sales taxes, tolls and other sources — makes it one of the two biggest transportation projects in commonwealth history.

Northam (D) touted the deal, saying he is “proud of the hard work and negotiations that have taken place over this past year,” and state Sen. Frank W. Wagner (R-Virginia Beach) in return offered praise for the embattled governor.

“I want to personally thank Governor Northam and his team for making this day possible,” Wagner said in a statement.

The winning consortium, Hampton Roads Connector Partners, is led by the U.S. arm of the Spanish construction firm Dragados. Plans call for a large boring machine to dig under the soft floor of a vital commercial and military channel, a construction method transportation officials said will cut down on disruptions to shipping traffic.

A pair of two-lane tunnels will be added, and Interstate 64’s four lanes will expand to eight during rush hour. The project is slated for completion in November 2025.

The improvements to the Hampton Roads Bridge-Tunnel are meant to ease daily snarls in the highly congested stretch between Hampton and Norfolk, which sometimes carries more than 100,000 cars a day. The original two-lane tunnels opened in 1957 and 1976.

“This project will help double capacity. Today, people can get backed up for miles at times. It can be 20, 30, 45 minutes,” Deputy Transportation Secretary Nick Donohue said.

The bulk of the money for the improvements will come from a regional gas and sales tax increase put in place as part of a statewide transportation funding law in 2013. The law has also been used by Northern Virginia to raise revenue.

There will also be $200 million in state funds under a program that prioritizes projects that reduce congestion, officials said. And Virginia is seeking about $1 billion in subsidized federal loans under the Transportation Infrastructure Finance and Innovation Act for the tunnel and other projects, Donohue said.

“This is a monumental day for the commonwealth, and Hampton Roads in particular,” said Del. Chris Jones (R-Suffolk), chairman of the House Appropriations Committee. “The fact that we have a contract for the new tunnel . . . is something many didn’t think they’d see in their lifetime. When you combine it with the other work that’s been done by the Hampton Roads Transportation Accountability Commission, it’s pretty amazing.”

The commission is the body set up to decide how to spend the regional transportation funds, and Jones, a member, pointed to its work on numerous area bridge and road projects.

Tolls will be charged on the Hampton Roads Bridge-Tunnel’s new lanes, while the old lanes will remain free, Jones said.

“We haven’t decided if they’re going to be 24-7, or if they’re going to be HOT lanes just during rush hour,” Jones said, using a term for toll lanes that allow car pools or vehicles with multiple passengers to travel free. Officials are conducting a toll study to inform the decision, he said.

Virginia’s Department of Transportation said the $3.3 billion effort to remake the bridge-tunnel is the biggest single transportation project in state history, though combining the two individual phases of Northern Virginia’s Dulles rail project, which is bringing the Silver Line to Dulles International Airport, totals $5.8 billion.

Despite the tumult in Richmond that started after a racist photo from the 1984 medical school yearbook of Northam surfaced about two weeks ago, Jones said that “it’s been business as usual for us at the Capitol.” He said legislators have worked well with Northam administration officials, who have been instrumental in the project.

Donohue said the procurement has been underway since December 2017, and Friday’s announcement was not timed for political benefit.

“This project represents the culmination of the region and the state working together in a bipartisan and collaborative fashion to get results for commuters in Virginia,” he said.

In addition to Dragados USA, members of the winning team, selected based on bids and technical specifications, are HDR and Mott MacDonald, the lead designers, and Flatiron Construction, Vinci Construction and Dodin Campenon Bernard, a France-based construction company.