ANTI-COLLISION TECHNOLOGY is moving closer to reality on the MBTA’s Green Line, even if the full realization will take a bit longer than T officials told the public earlier this year. 

The T will soon have enough equipment in place to roll out the first Green Line trolleys featuring on-board alerts about stalled vehicles or other obstacles on the tracks, more than 16 years after a fatal crash prompted federal regulators to recommend the system.  

A partial shutdown set to begin next week will allow the T to take another major step toward the “Green Line Train Protection System,” the first phase of which is now expected to be complete by next summer after a series of stops and starts. 

As one veteran official put it, the agency is “at a point where we can see the light at the end of the tunnel.” 

The technology relies on two primary features: equipment built into the cars and hundreds of “anchors” built alongside the tracks and platforms throughout the system. The anchors communicate with the on-board devices as trolleys move, allowing each vehicle to detect how close it is to others. 

In the first phase of implementation, Green Line operators will receive audible and visual alerts if the system detects a collision risk. The second phase, which is projected to be done in 2028, will add automatic speed control and braking. 

Crews will use the upcoming 15-day shutdown of the Green Line’s central trunk, primarily intended to replace the roughly 130-year-old wooden catenary wire trough, as an opportunity to finish installing anti-collision anchors underground. 

By the end of the year, T officials think they will have equipment in place for the Green Line Train Protection System from the endpoints at Union Square and Medford/Tufts through Kenmore Square, and also for the full D branch. Work to finish installation on the B, C, and E branches — the three other above-ground segments — will take place in the spring. 

The first trains using the new technology will roll out this winter, with full implementation set to be complete by the summer. 

“Each time the T introduces a trolley with the car-borne equipment between [December] and summer 2026, Green Line safety is enhanced more and more,” said MBTA spokesperson Joe Pesaturo. 

While the project moves ahead, the timeline has also been pushed back from prior public updates. 

In February, T officials said the first phase would be complete by December. A presentation MBTA general manager Phil Eng gave on November 20 slid that completion date back to mid-2026. 

Officials argue the MBTA is still ahead of schedule because the contract with equipment manufacturer Piper calls for the first phase to be done by March 2027, and that the earlier dates mentioned publicly instead represented Eng’s preference. 

“GM Eng challenged the GLTPS team and the contractor with an aggressive schedule to have Phase 1 fully implemented by the end of this year,” Pesaturo said. “While significant progress has been made, supply chain issues and design challenges made it difficult to meet the aggressive schedule.” 

The push for automated anti-collision technology on the Green Line traces back to Gov. Deval Patrick’s first term in office. 

In 2008, an operator on the Green Line’s D Branch ran through a red signal in Newton, crashing into the back of a stopped train. The operator, Ter’rese Edmonds, died and seven passengers were injured.  

The National Transportation Safety Board in 2009 said the incident could have been prevented if the MBTA, which already had anti-collision technology on most of its other rail lines, deployed a protection system on the Green Line. (That year, another Green Line crash injured dozens of passengers.) 

Little progress happened in the ensuing years. The T contracted with German firm BBR in 2019; five years later, after Eng took the helm as general manager, the agency scrapped the deal and reset the project. 

One of the recurring problems along the way has been the aged infrastructure on the Green Line, which officials say makes it difficult to slot in an off-the-shelf option for anti-collision technology. 

“The Green Line cars are not only old, but their body varies, even within the same model,” said Sam Zhou, the T’s chief engineer and assistant general manager. “What that means is it really creates design challenges for our team [and] made the integration work far more complex than it would be for a newer fleet.” 

In February, the MBTA’s board of directors approved a new $112 million contract with Piper. 

For some T employees, the fresh momentum carries special significance. 

Alicia Gomes, the MBTA’s executive director of light rail transportation, recalled starting her career at the agency as a light rail operator in 2007, one year before the fatal crash. 

The Green Line operator killed was a classmate of Gomes’s during training, and they came from similar backgrounds. Detailing her experience at a recent public meeting, Gomes said the incident left her questioning whether she wanted to continue to drive a trolley. 

“I experienced firsthand the 16-year-long wait without much movement on any sort of installation for Green Line Train Protection — lots of talk, but not much movement,” Gomes said. “Just in the last two years, with the current leadership and the administration, we have finally begun to see real, tangible progress, progress that many of us believe should have started more than 17 years ago, before the fatality.” 

“At this point,” she added, “we are finally at a point where we can see the light at the end of the tunnel.”