Scene of the crash between two Green line T trolleys near 971 Commonwealth Avenue in Boston on July 30th, 2021. Photo courtesy of Boston Fire Department

Campus Life

MBTA to Install Green Line Safety System to Prevent Crashes

Shuttle buses will replace B Branch trolleys June 20 to July 3, project then moves to C, E, and D Branches

Green Line B Branch trolleys will be replaced by shuttle bus service from June 20 through July 3 while the MBTA, facing increasing pressure to improve its culture of safety, installs a new safety system along the tracks from Kenmore all the way to Boston College.

What the T is branding as the Green Line Train Protection System (GLTPS) is commonly known as positive train control (PTC) and is intended to prevent collisions, overspeed derailments, and related problems. It was first recommended for the Green Line more than a decade ago, and it comes now as federal transit officials demand an improved safety culture at the MBTA.

The project launches as the T’s safety regime is under what the Boston Globe calls “intense scrutiny” by the Federal Transit Administration because of a rash of incidents, including a B Branch crash at Pleasant Street last year that injured two dozen people and resulted in the firing of the trolley operator. The most recent crash, on June 1, derailed two Green Line trolleys near the Government Center station and sent four MBTA operators to the hospital. And on June 14, passengers had to disembark from two Green Line trolleys after they accidentally “coupled” at the Government Center platform, temporarily suspending service between Park Street and Government Center, forcing the passengers to exit via an underground tunnel. Speaking at the MBTA Wednesday morning, one federal transit official said changes are needed as a “result of continuous safety violations and a failure to take urgent corrective actions.”

PTC alerts the crew of a trolley “when it detects the possibility of either a train-to-train collision or a train that’s moving too fast along the line or through a work zone,” according to the T: “The safety technology monitors a train’s location, direction, and speed in real time. If the crew does not respond to an alert, PTC will take over and automatically stop the train.”

Positive train control is federally mandated for many intercity rail systems and is already in place on the MBTA Red, Blue, and Orange Lines and commuter rail. The National Transportation Safety Board reportedly first recommended positive train control for the Green Line back in 2008, after a crash in Newton that killed a trolley operator.

The Green Line Train Protection System installation was already planned last July when the westbound B Branch trolley rear-ended another at Pleasant Street at excessive speed. However, the T sped up the project by a year after the crash.

“The GLTPS project will prevent those kinds of accidents from happening,” MBTA general manager Steve Poftak told board members in January, according to the Globe.

This summer’s work involves installing “balises,” transponders that communicate between the train and the signal system, along the tracks, as well as wiring junction boxes and new signal heads. The project will also include more disruptive work not related to the safety system, such as track replacement and intersection improvements.

But the good news is that all of that has already been done on the tracks along the Charles River Campus as part of the Green Line Transformation Project. So—aside from the switch to shuttle buses—disruptions should be relatively minimal between Kenmore and Babcock stations from June 20 through July 3.

From Packard’s Corner west, though, there will be significant impacts, including lane closures, parking changes, noise, and the use of heavy equipment during the 12 days of accelerated construction, which the MBTA is calling a “surge.” Notably, the T will replace 3,200 feet of track between Packard’s Corner and Linden Street.

The project will then move to the C Branch (July 11-22), the E Branch (August 6-22), and the D Branch (three separate nine-day closures between September 24 and October 30). In each case, trolleys will be replaced by shuttle buses for the duration of the work. Planning is underway for work on the Green Line tunnels east of Kenmore in 2023.

Closing the tracks completely for a 24-hour-a-day “surge” means work on the B Branch can be completed in 12 days, rather than the four to six months required to accomplish the job working part-time at night and on weekends.

The T says low-rise accessible buses will be used as shuttles, stopping at existing Route 57 bus stops along Comm Ave from Blandford Street to Babcock Street, at equal to, or better than, the frequency of trolley service. West of Babcock, some stops may be moved, but will generally be close to existing trolley stations. Shuttles will not stop at Packard’s Corner, Allston Street, or Warren Street, however.