Maryland will design bus lanes for upper Montgomery County as part of adding toll lanes to Interstate 270 and the Capital Beltway, the state’s transportation chief said Tuesday. The pledge appeared aimed at winning support for the toll lanes proposal one day ahead of a key vote that will determine the project’s future.

Advocates of the toll lanes plan backed by Maryland Gov. Larry Hogan (R) said they were cautiously optimistic that the commitment to improving mass transit would garner the highway project enough votes Wednesday to keep it moving forward. However, opponents and supporters said the vote tally among Washington-area leaders on the Transportation Planning Board will be close.

The board cut the project from the region’s long-range transportation plan last month, making it ineligible for federal environmental approval. The Maryland Department of Transportation is seeking to get it restored. The project was rejected in a 16-to-13 vote, but the next tally is difficult to gauge, because it will be based on a complex system weighted by population.

In a letter to the Montgomery County Council, Maryland Transportation Secretary Gregory Slater said the state would design bus lanes using some of the $145 million upfront payment expected from a private team selected to build the toll lanes.

The letter said the money could go toward one of two projects — the long-planned Corridor Cities Transitway in the I-270 corridor between the Shady Grove Metro station in Rockville and the Metropolitan Grove MARC commuter rail station in Gaithersburg, or a bus rapid transit system along part of Rockville Pike (Route 355).

Slater wrote that he wanted to “further reaffirm our commitment to a multi-modal effort” to relieve traffic congestion. The state “will also collaborate with you on a plan for the final delivery, construction and operations” of the transit system as part of the toll lanes project, Slater wrote.

Montgomery Council member Hans Riemer (D-At Large), who said he negotiated the agreement with Slater, said he was told the state would pay for the transit construction using its share of toll lanes revenue.

The council responded with a statement saying a majority of its members would endorse the toll lanes proposal. Montgomery County Executive Marc Elrich (D) said he would continue to oppose it.

In an interview, Elrich said additional state spending on either bus project would not offset the environmental and community damage caused by widening the highways. He said the state’s plan to use private financing would result in exorbitant tolls that most motorists cannot afford.

“I’m yawning,” Elrich said of MDOT’s transit offer. “It’s nice and we wish it were more, but it doesn’t really get us to where we need to go.”

In a statement, five of the council’s nine members said the state’s “new commitment” to transit investments had helped win their support. For more than a decade, county officials have asked MDOT for a bigger American Legion Bridge and an expanded Beltway to the I-270 spur — both part of the toll lanes project, the statement said.

“The bottom line is they are offering to pay for a major transit project with toll revenue,” said Riemer, who is running for county executive. “That’s a breakthrough in our deliberations, and it’s very encouraging.”

Montgomery council member Craig Rice (D-District 2), whose district includes the I-270 corridor, said the bus lanes would serve residents who cannot buy their way out of congestion via tolls or who want alternatives to driving. He said bus lanes along Rockville Pike would connect the Clarksburg area with the Shady Grove Metro station.

“For us, it’s really been about understanding that it’s got to be more than just improving lower I-270 and the American Legion Bridge,” Rice said.

Some council members said MDOT’s transit offer was not enough to overcome their concerns.

“We all want to relieve traffic congestion and we all want to increase public transportation,” council member Evan Glass (D-At Large), a planning-board member who was not part of the council’s endorsement, said in a statement. “But this ‘deal’ is not it. I simply wish that Governor Hogan had engaged local leaders from the start.”

Also on Tuesday, 77 members of the Maryland General Assembly wrote to the planning board asking that it uphold its June rejection of the toll lanes plan, saying it “does not enjoy a regional consensus” and “fails to move the region forward on environmental justice.”

The transit offering came a week after MDOT released a list of $1.23 billion worth of road and transit projects, including the Corridor Cities Transitway, that it said would need to be cut to offset private financing that would be lost as part of the toll lanes plan. Some local leaders who have objected to the highway widening — and the potential effects on parkland and neighborhoods — had said Hogan was trying to strong-arm them into supporting the toll lanes.

The I-270 corridor is home to dozens of biotech companies, including coronavirus vaccine developer Novavax and MedImmune, the biologics research arm of coronavirus vaccine developer AstraZeneca. It also includes the Universities at Shady Grove, a campus for Johns Hopkins University and the National Cancer Institute.

But the clustering of job centers, as well as the fact that I-270 is a major thoroughfare between the D.C. region and more-affordable homes in Frederick County, western Maryland and points beyond, bring daily traffic jams. County growth plans require the Corridor Cities Transitway’s construction to be funded before much of the development proposed for west Gaithersburg could occur.

The project has been dormant since 2019, when the Hogan administration cut all state funding after previously saying it had anticipated “an investment” in it as part of the toll lanes plan announced in 2017.

Gaithersburg City Council member Neil Harris, a supporter of toll lanes, said he hopes the council’s endorsement will convince planning-board members from Northern Virginia and the District that the idea has broad support among local officials, even if Elrich and some Montgomery council members still object.

“We’ve been telling them Maryland is, by no means, unanimous on this,” Harris said.

Under Hogan’s plan, a private team would build the lanes and finance their construction in exchange for keeping most of the toll revenue over 50 years. Both highways would get two toll lanes in each direction, with the prices adjusting to keep their traffic free-flowing. The regular lanes would be rebuilt and remain free, while one of the I-270 toll lanes would come from converting a carpool lane.

The first toll lanes would extend on the Beltway from the Virginia side of the American Legion Bridge to the I-270 spur and then up I-270 to Interstate 370. The aging bridge would be replaced with a wider span. The northern part of I-270 to Frederick is still in the early stages of a federally required environmental review.