Traffic flows along interchanges that link the Capital Beltway and I-270. (The Washington Post/Katherine Frey)

Nearly 60 Democratic lawmakers are asking the Board of Public Works to delay a vote on a plan that could lead to a toll lane expansion of two highways in the D.C. area.

The letter released Monday is the latest effort by opponents of Gov. Larry Hogan’s proposal to ease congestion on a portion of the Capital Beltway and Interstate 270. The three-member board led by Hogan is scheduled to vote Wednesday on a request to designate the projects as a public-private partnership and begin the process of soliciting a developer.

“Your decision at this meeting will have lasting consequences for our constituents and our state,” lawmakers wrote in the letter.

Lawmakers who signed the letter are asking that the project be split into smaller chunks before being designated a public-private partnership and that any approvals be delayed until an environmental impact statement is completed. The letter also asks the board — comprised of two Democrats, Comptroller Peter Franchot and Treasurer Nancy Kopp, and Hogan — to “enforce promises that the governor made not to seize any homes or businesses along the path of the project.”

Del. David Moon, D-Montgomery, said lawmakers would like to see the project split into smaller components as a compromise.

“There is great resistance to the widening along some of the inside-the-Beltway segments, but much less so along other portions of the proposed widening,” Moon said. “The issue will likely be whether you can finance the project without the highly contested sections included, but I think looking at alternatives and hybrid approaches is a reasonable ask.”

Michael Ricci, a Hogan spokesman, said the letter from lawmakers was “a great representation of how there is a lot of misinformation about our plan out there.”

“Good news: We are well on our way to doing all of the things that these legislators request,” Ricci said. “We look forward to implementing these ideas as part of our plan to fix the region’s soul-crashing traffic.”

Ricci said each phase of the project would come before the board for approval. He added that an environmental study is being conducted concurrently “emulating best practices in other states.”

Last month, Hogan created a work group he said would solicit input from advocates for mass transit. Ricci said the state plans to provide incentives to partners in the project to avoid condemnation of private homes or businesses.

The letter comes on the same day that a coalition of 43 transit, environmental and community groups urged the board to reject the proposal.

“This proposal fails to protect the best interests of Maryland’s taxpayers, communities, the environment and ignores sensible alternatives included in County Master Plans,” the coalition wrote in its letter. “This proposal tramples years of transportation planning and research by placing the political agenda of private construction companies over the wants of Maryland citizens.”

The board delayed a vote in May after a group of lawmakers questioned the propriety of taking up the issue when one member — Treasurer Nancy Kopp — vacationed out of the country.

Signatories on the May letter were limited to lawmakers from the affected areas. This time, Moon said, Democratic legislators from around the state were asked to sign on.

The board is scheduled Wednesday to consider a proposal that designates the highway widening, and also would include using toll lanes, as a public private partnership. Hogan announced the widening plan in September 2017 as part of larger $9-$11 billion proposal to alleviate traffic congestion. That larger proposal could one day include the additions of toll lanes along the Baltimore-Washington Parkway.

The combined costs of the projects are considered to be the largest public-private partnership proposal in the country. By comparison, the 16.2 mile Purple Line light-rail line connecting Bethesda to New Carrollton is expected to cost $2.4 billion.

Board approval of the request for the two highways would allow the Maryland Department of Transportation to solicit for developers for each phase of the project.

But opponents have raised concerns about environmental impacts, the potential for homes to be taken by eminent domain, and costs for using the lanes.

Moon said many areas that have the strongest neighborhood and elected official opposition “do have eminent domain issues, and Hogan attempted to get through the last election by promising not to seize any homes or businesses. It is understandable that these residents are now upset that those promises may have been false.”

Kopp and Franchot, are the target audience of the letter. The Democratic former legislators both hail from Montgomery County.

“We haven’t heard for sure how either will vote,” said Moon. “Given recent speculation about Franchot’s political future, I’m hopeful he might be willing to at least push for more information and detail before rushing to a vote.” Franchot is believed to be a potential candidate for governor when Hogan’s second and final term ends.

Len Foxwell, Franchot’s chief of staff, said the comptroller “is carefully reviewing the extensive body of information that has been provided on this proposal and plans to present detailed follow-up questions to the Department of Transportation at Wednesday’s meeting.”

A spokeswoman for Kopp said the treasurer “continues to share the concerns raised recently by the county governments and set forth in this letter by legislators. She hopes the Department of Transportation will take these issues seriously and respond to them in a positive, cooperative and productive manner.”