The Maryland Board of Public Works voted 2 to 1 Wednesday to allow the state to solicit private companies to build and operate toll lanes on Interstate 270 and the Capital Beltway as part of Gov. Larry Hogan’s plan to ease traffic congestion in the Washington suburbs.

In a change to Hogan’s initial proposal, the I-270 lanes will be built first. Adding toll lanes to the American Legion Bridge and Interstate 495 in Montgomery and Prince George’s counties, which has been more controversial, will be phases 2 and 3.

Hogan said the American Legion Bridge, which connects Maryland and Virginia along the Beltway, needed the most immediate relief. However, he said he would “reluctantly” prioritize I-270 because it was less controversial than the Beltway, where widening would require destroying more homes.

“This transformative project that we’re voting on today is about finally taking the first step to move forward and to finally take action on an issue that unfortunately elected officials have literally ignored for decades,” the Republican governor said. “It will result in less traffic, more peace of mind, cleaner air, and a much better quality of life for hundreds of thousands of Marylanders for decades to come.”

He added, “I’m moving forward with 270 because more people want to do 270.”

Delaying the bridge and Beltway portion by two years, he said, would give state transportation officials more time to work with leaders in Montgomery and Prince George’s to address their concerns.

The vote designating the toll lanes project as a public-private partnership allows the Maryland Department of Transportation to begin pursuing proposals from teams of companies.

The consortiums would design, build and operate up to four toll lanes on each highway — and pay for the construction — in exchange for keeping most of the toll revenue over 50 years. They also would rebuild decades-old overpasses and the existing lanes, which will remain free.

Hogan has said the contracts — valued at more than $11 billion — will represent the largest public-private partnership ever in the United States.

The approval is significant because it starts a relatively fast-paced process in which companies will spend millions of dollars to put together detailed engineering proposals and line up financing.

State officials have said they would release a “request for qualifications” to the private sector within a few months of the board’s approval and seek the board’s okay for the first of five 50-year contracts in fall 2020. It’s unclear how changing the order to solicit proposals for I-270 first might affect that schedule.

All federally required environmental reviews would be complete before any contracts are finalized, transportation officials said.

Hogan and comptroller Peter Fanchot (D) voted for the plan. Treasurer Nancy K. Kopp (D), who is appointed by the General Assembly, voted against it.

The Maryland Board of Public Works also voted 2-1 to approve Franchot’s amendments to allow buses to use the toll lanes free and to study the feasibility of an elevated monorail line adjacent to I-270.

Additionally, 10 percent of the state’s share of any toll revenue would be allotted to mass transit in Montgomery and Prince George’s.

The governor’s support of Franchot’s amendments appeared to be a peace offering to transit advocates and elected leaders in Montgomery and Prince George’s who had complained that transit had been given short shrift in Hogan’s “highways-only” traffic relief plan.

Franchot also addressed a risk that state transportation officials probably have been weighing — the fact that growing political discord over the project could discourage companies from bidding on, or loaning money to, a project that lacked broad public and political support.

“I can’t imagine the private sector not being intensely interested in this,” Franchot said, “because I think a lot of the opposition from the local jurisdictions will begin to be mollified by . . . the changes that we’re making today.”

Hogan changed the order of the toll lane construction after more than two hours of discussion, including sometimes testy exchanges between the governor and some toll opponents, during a packed meeting at the State House in Annapolis. Afterward, supporters and opponents of the plan were left scratching their heads and asking one another what had just happened.

It was unclear, for example, where the lanes will be built first — on the lower part of I-270 between the Beltway and I-370, which state officials have said would be more lucrative for the private sector, or between I-370 and Frederick, where northbound traffic grinds to a halt every evening as the highway narrows from six lanes to two.

Widening the upper portion first could delay the project by two years because the federally required environmental impact study, which typically takes about that long, hasn’t begun for that section.

Even so, the impacts for I-270 are expected to be much less significant than for the Beltway because I-270 generally has more public right of way.

So far, the state’s study has found that up to 34 homes and four businesses, almost all in Montgomery, would be destroyed to widen the Beltway, along with pieces of another 1,262 properties. The study of the lower part of I-270, south of I-370, so far has found no homes or businesses that would be destroyed and up to 234 pieces of property that would need to be taken.

Maryland transportation officials did not say when construction will begin or how long it is expected to take. Hogan sounded least certain about the timing of adding toll lanes to the Beltway between Interstate 95 and Maryland Route 5 in Prince George’s, where many residents have said they’re concerned about the cost of tolls.

The Beltway in Prince George’s, Hogan said, “could perhaps be done at some point in the future.”

Even supporters of toll lanes on I-270 said expanding it before the Beltway could make morning traffic jams worse, with a much wider I-270 dumping traffic onto a four-lane Outer Loop and a bridge that’s already backed up daily.

“Coming south in the morning, the backup is at the spur and the bridge,” said Marilyn Balcombe, president of the Gaithersburg-Germantown Chamber of Commerce, which supported adding the I-270 lanes. “You can’t fix I-270 south without fixing the bridge.”

Maryland Transportation Secretary Pete K. Rahn and state highway administrator Greg Slater were unavailable for questions after the vote.

Erin Henson, an MDOT spokeswoman, said agency officials were still sorting through the details of what had been approved.

“The exact sequencing needs to be worked out,” Henson said, referring to I-270.

Outside the meeting room after the vote, Franchot said he wasn’t certain whether starting with I-270 meant the entire highway or part of it first.

“I think that’s all going to be sorted out down the road,” Franchot said. “But the key is the governor listened to Montgomery County leaders and citizens to change the order. That gives them an enormous amount of time and should generate goodwill for future discussions.”

Kopp said she opposed the toll plan because MDOT hadn’t answered many of her questions.

“We don’t have all the numbers behind the financing of the proposal,” Kopp said. “We’re making a commitment for the next 50 years or more, and we don’t know what the environmental impacts are going to be.”

Under the plan, the new lanes would have variable tolling, the cost to use them rising with congestion to keep traffic flowing smoothly.

Slater, the highway administrator, told the board that the formula for calculating the tolls will be determined in each contract, but that the board for the Maryland Transportation Authority will approve a range.

Franchot asked Slater what would happen if toll revenue came up short, leaving the private partner unable to pay off its construction debt. Would the state have to cover any of it?

In “most cases,” Slater said, the bondholders and lenders would “take over” the toll lanes, which the state would continue to own.

“We’re not on the hook in any way,” Slater said.

However, he said, the state would have to “compensate” the private partner for its construction costs if the state terminated the contract.

Montgomery County Council Member Tom Hucker (D-District 5), chair of the council’s transportation committee, called the vote a “breakthrough” because local officials finally felt as though they were being listened to.

“The logjam has been broken because they indicated their willingness for the first time to accommodate our residents’ concerns, so this is fabulous,” Hucker said. “270 needs to be done, and we agree on that, so let’s do it.”