The Massachusetts Bay Transportation Authority (MBTA) and the City of Boston have "tentatively" agreed to eliminate a major source of delays on the Green Line with a new dedicated transitway that will run down the middle of Huntington and South Huntington avenues in the city's Mission Hill neighborhood, StreetsblogMASS reported Aug. 25.

In early August 2025, the MBTA issued a "request for qualifications" for engineering firms to prepare shovel-ready plans for "accessible station designs for Mission Park, Riverway and Heath Street stations [as well as] new transitway and track improvements" on the Green Line's E branch.

In an update posted to the city's website, Boston officials confirmed that "based on what we have learned in our conversations with community members, with the MBTA and with other stakeholders, such as the Boston Water and Sewer Commission, the project will be moving forward with a centered Green Line track with dedicated lanes for trains and buses. Stops will be served by side platforms."

Existing Mission Hill Stations Known Safety Hazards

The E branch between Brigham Circle and the end of the line at Heath Street constitutes the only part of the MBTA's rapid transit system where trains still share a roadway with motor vehicles.

Those streets — Huntington and South Huntington Avenues — currently have four lanes for moving vehicles, with Green Line tracks in the center lanes and two parking lanes along the curbs.

Besides forcing transit riders to wait in traffic, this design also directs passengers to board and disembark in the middle of a busy street.

Both Huntington and South Huntington Avenue have been flagged as high-crash streets under the City of Boston's Vision Zero prioritization plan.

The proposed center-running transitway would mitigate both of those problems by keeping cars and trucks off the Green Line tracks and building new, Americans with Disabilities Act-accessible boarding platforms alongside the new transitway — similar to the Green Line's C branch stops on Beacon Street in Brookline.

Converting the center lanes to a dedicated transitway would consolidate private vehicle traffic into a single lane in each direction — a roadway layout that is considerably safer. The new boarding platforms would require additional roadway space and might require the removal of some on-street parking zones.

A Green Line As Well As a Busway

The Mission Hill project also could benefit two of the MBTA's frequent-service bus routes, the 39 and the 66.

Officials from both the MBTA and the city confirmed that the transitway concept is being designed for both trains and buses, and bus passengers would share the same stops as Green Line riders at the new Mission Park, Riverway and Heath Street stations.

During peak hours, buses on those two routes operate with average speeds below 12 mph, according to data from the Boston Transportation Department.

Besides meeting accessibility requirements, the MBTA also needs to redesign many of its Green Line stations to accommodate its new "Type 10" trains, which are currently scheduled to enter service in 2027.

Because those trains are longer, the agency has been consolidating some Green Line stops to lengthen the platforms that the new trains will require.

In previous presentations, MBTA officials have indicated that Fenwood Road, which is only approximately 500 ft. from the Brigham Circle stop, and Back of the Hill, 400 ft. away from the Heath Street transit stop, would be eliminated.

MBTA officials told StreetsblogMASS that the new E Branch transitway and stations are currently scheduled to begin construction in the fall of 2027; the agency hopes to open the new facilities before the end of 2029.

Plans also are being advanced by the MBTA to improve accessibility on two other Green Line branches before the end of the decade.

One that would rebuild and consolidate several stops along the C branch through Brookline is currently under contract and has an expected completion set for next year. The other will upgrade 10 stops on the B branch along Commonwealth Avenue through Brighton. It, too, is slated to begin in 2026, with a finish date likely in late 2027, StreetsblogMASS noted.