Maryland transportation officials are pushing for new toll lanes that they say would provide the only affordable traffic relief for the Washington suburbs by allowing motorists to buy their way out of backups on the Capital Beltway and Interstate 270.

But the idea is drawing criticism from leaders in Montgomery and Prince George’s counties who say they and residents have been left out of discussions of where and how the lanes should be added — or whether they’re the best way to alleviate the traffic misery. In particular, they say, they have been given mixed messages about the risk to homes and businesses if the highways are widened to accommodate up to four new lanes each.

While campaigning for reelection in September, Maryland Gov. Larry Hogan (R) told a toll lane opponent in a videotaped exchange at a Gaithersburg parade, “Not a single house is ever going to be taken down.”

But Maryland Transportation Secretary Pete K. Rahn has softened that stance. The governor, Rahn has said, asked him to “prioritize and incentivize” bidders to spare homes in their design proposals — wording that some critics say undermines what many had taken as a promise.

Local officials say they have heard from residents worried about whether to try to sell their homes before they could be torn down or end up with a highway sound wall in their backyard.

Montgomery County Council member Tom Hucker (D-District 5), chair of the council’s transportation committee, said the state has ignored local concerns on a “relatively radical” proposal.

State officials “basically said they’re going to plunge forward,” Hucker said. “That has created an enormous amount of fear and anxiety in Silver Spring and elsewhere.”

Prince George’s County Council chair Todd M. Turner (D-District 4) said he sees state officials “giving themselves some wiggle room” about potential impacts on adjacent communities.

“There are serious concerns,” Turner said. “This has been a top-down approach from the state saying how we need to solve this issue. . . . We need to be engaged in this process, and not in a perfunctory kind of way.”

Discussion about the state’s tolling plan has heated up in recent weeks as state transportation officials briefed the Montgomery and Prince George’s councils in advance of public workshops scheduled for April. The meetings are intended to seek public input on seven alternatives that the state has kept for detailed analysis as part of a federally required environmental impact study.

The remaining options focus on choosing between a high-occupancy toll (HOT) lane system, which carpoolers may use free, and express toll lanes that require all users to pay. The state recently abandoned transit-based options, such as building dedicated bus lanes.

Next month’s public airings probably will not provide the details many residents want. State transportation officials say they won’t know if any homes, businesses or private parcels would be affected — or how much it would cost to spare them — until they receive the bidders’ design proposals in summer 2020.

“I believe it’s doable to not take any homes,” Rahn said in an interview Thursday. “I’m hoping the designs avoid all the homes, but we won’t know until we get their proposals.”

Overall, state officials have said I-270 has more right of way than the Beltway. Rahn said he doesn’t “see any areas” along I-270 where homes or businesses would need to be taken.

He told the Prince George’s council that “in some cases I think there will be land — land — but not necessarily homes” required for Beltway widening.

The study so far has focused on I-270 between the Beltway and I-370 in Gaithersburg and on the Beltway between the George Washington Parkway in Virginia and Route 5 in Prince George’s, including the notoriously traffic-choked American Legion Bridge. Another part of the study beginning in April will examine adding lanes further north on I-270, between I-370 and Frederick. The Beltway analysis will extend down to the Woodrow Wilson Bridge, near the National Harbor.

Rahn said the study will show the number of homes and businesses that would need to be demolished in a “traditional footprint” for each scenario. However, he said state officials believe the bidders will find “shockingly innovative” ways to avoid more properties, such as by cantilevering some lanes over others. He said proposals will be awarded extra points in the selection process for sparing homes.

If all goes according to plan, Rahn said, construction could begin in mid-2022. The opening dates — construction is expected to be staged — would depend on the designs chosen, he said.

Hogan surprised local officials when he announced the highway expansion plan as a public-private partnership in September 2017. He said the state could get $9 billion to $11 billion worth of toll lanes at no cost by partnering with companies that would design, build, finance and operate the lanes’ construction in exchange for keeping the long-term toll revenue.

It would be the biggest public-private partnership in the country, Hogan said, and would provide the only affordable relief from backups that extend seven to 10 hours daily.

Another proposal to add toll lanes to the Baltimore-Washington Parkway is on hold unless the state can gain control over the federal government’s 19-mile segment of the 29-mile roadway, Rahn said.

Officials in Montgomery and Prince George’s say they remain perplexed why the state scrapped the idea of expanding transit, such as beefing up MARC commuter rail or building the long-studied Corridor Cities Transitway bus system in the I-270 corridor.

Moreover, they say, it does not make sense to focus first on expanding the southern portion of I-270 when it is the northern section that bogs down daily where the highway narrows near Clarksburg.

Rahn said not enough motorists are projected to use the toll lanes north of I-370 to pay for their construction. That requires staging the expansion so toll revenue from the Beltway and lower part of I-270 could pay for building the lanes north of I-370, he said.

The state also has made a “huge investment” in the area’s transit network, Rahn said, noting construction underway on the light-rail Purple Line inside the Beltway and the state’s additional contributions to rehabilitate the aging Metro system.

Even so, he said, expanding transit would not meet the traffic-relief needs under study because that would require ongoing state subsidies and would not alleviate freight traffic.

The tolling plan is also getting attention in the Maryland General Assembly. A legislative proposal that would have allowed counties to veto state tolling projects in their jurisdictions recently died in the House.

Del. Kumar P. Barve (D-Montgomery), who chairs the House Environment and Transportation Committee, said the proposal would not have passed in the Senate because of concerns that it would set a bad precedent statewide.

However, he said, he and other lawmakers concerned about the toll plan’s potential impacts on residents are pushing the Senate to pass other legislation recently approved by the House. It would require the state to complete environmental studies on projects before evaluating public-private partnership proposals on them. That, Barve said, would ensure that projects don’t gain too much momentum before being properly vetted.