Why a group is threatening to sue MassDOT over a change to an I-93 carpool lane

“Punishing people for carpooling and taking public transit is the exact opposite of good policy."

Traffic on I-93 South in Somerville during the morning sunrise commute in 2016. Dina Rudick / The Boston Globe

This past spring, Massachusetts transportation officials opened up the southbound carpool lane on I-93 — from Medford to the Zakim Bridge in Boston — to single drivers at all times as part of an effort to relieve traffic impacts from a two-year Tobin Bridge construction project.

Now, they’re facing a potential lawsuit.

The separated high occupancy vehicle (HOV) lane had previously been reserved for buses and cars with two or more people during the weekday morning commute (6 a.m. to 10 a.m.). The state constructed HOV lanes on I-93 (there’s also one south of Boston) in the 1990s as part of an effort to make sure the Big Dig met state and federal clean-air laws, by providing drivers an incentive — potentially a quicker commute — to use more efficient means of transportation.


And while the lanes have struggled with low ridership and sparse enforcement, the Conservation Law Foundation says that the Department of Transportation’s move to open the lane to all traffic is illegal and hurting those who used it in the midst of the region’s worsening congestion crisis. And the Boston-based environmental nonprofit is threatening to sue.

“With the daily traffic nightmare on our roads, opening this lane to all cars is short-sighted, slows commutes for bus riders, and violates the law,” Staci Rubin, a senior attorney at CLF, said in a statement Tuesday.

“Punishing people for carpooling and taking public transit is the exact opposite of good policy,” Rubin continued. “For the sake of our environment and the health and well-being of residents north of Boston, the state must realize its mistake and undo this change immediately.”

According to CLF, the decision to allow single drivers to use the HOV lanes, which was criticized by local transportation advocates at the time, has resulted in “significantly longer commute times” for the carpoolers and bus riders who used the lane. Citing state data, the group said that several bus routes ran up to eight minutes slower this past June and July compared to their travel times during those months in 2018. Those delays disproportionately impact people of color and lower-income riders, they said.


In a letter to Gov. Charlie Baker and several state transportation officials, the CLF also argued that the administration had violated state and federal laws regulating the implementation of the HOV lanes by making the change without providing any alternatives. The group said the state has 60 days to respond before their lawsuit is officially filed.

Transportation officials say the change is temporary and intended to benefit “all travelers” during the Tobin Bridge project, which is planned to be completed by the end of 2020.

“MassDOT does not plan to make this condition permanent as the opening of the I-93 southbound HOV lane in Somerville and Medford is one of several temporary measures being undertaken by MassDOT to relieve North Shore congestion for all travelers related to the Route 1 Chelsea Viaduct and the Tobin Bridge projects,” Jacquelyn Goddard, a spokeswoman for the agency, told Boston.com in a statement.

During the construction, MassDOT is also funding several temporary measures meant to encourage public transit use, such as providing additional MBTA Blue Line trains, offering free fares to inbound Silver Line riders in Chelsea, and allowing Charlie Cards to be accepted on commuter rail trains between North Station and Chelsea.

Goddard added that MassDOT “looks forward to meeting with CLF in the near future to address the group’s concerns.”


In the notice of their intent to sue, the CLF included a letter signed by 20 local state legislators expressing concern about HOV lane change. And while they acknowledged the state’s efforts to expand access to the Blue Line, Silver Line, and commuter rail in the wake of the Tobin Bridge project, the group indicated that those measures weren’t enough.

Rep. Kenneth Gordon, who commended the state for providing some alternatives, wrote that “eliminating the HOV Lane for such an extended period” still undermines the stated overall goal of “easing traffic congestion by placing emphasis on sustainable transportation.”

CLF President Brad Campbell concurred.

“Whether temporary or permanent, any change to the HOV lane requires MassDot to follow the law and make sure that the change does not result in dirtier air, more congestion, and poorer health in affected communities,” Campbell told Boston.com in a statement. “I have made clear to Secretary Pollack that CLF is open to alternatives that clear this bar.”