A bill that would have delayed Maryland Gov. Larry Hogan’s (R) plan to add toll lanes to the Capital Beltway and Interstate 270 died in the General Assembly on Monday, after a key committee chairwoman said motorists need traffic relief as soon as possible.

Sen. Nancy J. King (D-Montgomery), chair of the Senate’s Budget and Taxation Committee, said she didn’t allow the bill to proceed to a committee vote during the legislative session that ended Monday night because state Transportation Secretary Pete K. Rahn told her it would result in stalling traffic relief for three years.

The bill would have delayed the state’s ability to seek a public-private partnership to design, build and help finance the lanes’ construction until after it completed an environmental impact study. Such a study will show how many homes and businesses would have to be demolished to make way for any highway widening, as well as how doing so would affect air quality, parkland, streams and other environmentally sensitive areas.

Supporters of the legislation said Hogan’s proposal — which would add up to four toll lanes on each highway — is moving too quickly and lacks oversight because the state plans to begin soliciting proposals from companies this spring, before completing the environmental impact study.

“While I think we need to be cautious with [public-private partnerships] — and [Rahn] understands that — I don’t want to wait three years to have any kind of action,” King said in an interview Tuesday. “I don’t want to tie their hands in any way. I want to see what the plan is. But [Rahn] said they were willing to work with county people and senators and delegates, so I’m going to hold them to that."

King said she favors adding two toll lanes — one in each direction — to both highways, but she wants the transportation department to be able to solicit ideas from the private sector.

“I think we have to go along with the department at this point and see what they have to offer,” King said. “I really don’t believe it’s going to be crammed down our throats.”

Supporters of the bill included other lawmakers from both Montgomery and Prince George’s counties, both county councils, Montgomery County Executive Marc Elrich (D), environmental groups and community activists from neighborhoods along both highways. Many said state officials hadn’t been transparent enough about how any highway widening would affect nearby communities. They also said the state shouldn’t have rejected the option of reducing traffic by expanding transit options, such as MARC commuter rail in the I-270 corridor.

Del. Jared Solomon (D-Montgomery), who sponsored the bill, said he was disappointed because it was “a responsible way of providing oversight on the project.” He said residents who live along the highways have been given “very little” information.

“I’m at a loss as to why we wouldn’t wait to thoroughly study the impacts of a project before we move forward” with soliciting proposals to build it, Solomon said.

Some toll lane opponents said they will now try to persuade the state’s Board of Public Works to reject the Maryland Department of Transportation’s plan to begin soliciting private proposals. With Hogan holding one of the board’s three votes, they would have to persuade both of the other two members — Comptroller Peter Franchot (D) and Treasurer Nancy K. Kopp (D) — to reject the plan when they vote sometime this spring.

Josh Tulkin, director of the Maryland Sierra Club, said the Senate had “put our environment, health and future at risk” by not voting on the measure.

“Governor Hogan and MDOT are rushing a proposal to massively expand I-495 and I-270 without even understanding how these plans would impact our air, water and climate for generations to come,” Tulkin said in a statement.

The bill passed the House 96 to 42. Another proposal aimed at stopping the project died in the House. It would have allowed counties to veto state tolling projects in their jurisdictions.

Under Hogan’s plan, a team of companies would design, build and help finance the toll lanes’ construction — they’re estimated to cost $9 billion to $11 billion to build — in exchange for operating them and keeping the toll revenue long-term. The governor said it would be the largest public-private partnership in the country and, at no cost to the state, would provide the only affordable way to relieve stifling congestion that will get worse as the Washington region grows.

The state is conducting the federally required environmental impact study simultaneously with the partnership solicitation process. However, state transportation officials have said companies typically won’t sign a contract until a final impact study is completed and approved by the Federal Highway Administration.

At an April 3 hearing on the bill, Rahn said holding off on soliciting private proposals until after the environmental study is finished would delay the project by at least two years and add more than $300 million in construction costs for every year of delay.

King said she’s sympathetic to residents who have told her they feel “tied up” while the tolling plan proceeds, not knowing whether they can sell their homes or if they might be targeted for demolition.

She said Rahn told her he didn’t believe any homes along I-270 would be demolished, “but if there were, it would only be a couple.” She said that he didn’t provide any number for homes that could be affected along the Beltway but that the state “would like to have none and will take the least amount possible.”

Public workshops on the seven alternatives still under consideration for the toll plan are scheduled to be held this month.