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On the T’s Green Line, another serious crash and questions about the lack of safety technology

The National Transportation Safety Board is investigating a crash between two Green Line trains near 971 Commonwealth Ave. on July 30 that resulted in multiple injuries. It’s the NTSB’s third such probe of a Green Line collision in 13 years.Barry Chin/Globe Staff

Brian Sirman boarded the Green Line last month to head to a friend’s house for dinner, his only worry being whether the train would get him there on time.

But barely 20 minutes into his July 30 ride, another trolley traveling three times the speed limit slammed into the rear of Sirman’s train, launching him from his seat and propelling others across a smoke-filled trolley car.

The crash, which sent 27 people to the hospital, could have been avoided ― if only the MBTA had acted faster on repeated warnings to upgrade safety technology on the nation’s busiest light rail system.


In 2009, the MBTA had been told it could prevent such a collision with safety technology, but after 12 years of studies, experimentation, and a series of other crashes, the equipment still hasn’t been installed, making the Green Line the only part of the transit system without the extra protection.

“It surprises me and worries me the T didn’t take action sooner,” said Sirman.

The story behind the missing safety technology is a tale of eye-popping cost estimates, failed testing rounds, and a years-long process to pick an alternative solution that will cost $170 million and isn’t expected to be fully implemented until 2024.

The drawn-out process unfolded as the Massachusetts Bay Transportation Authority installed the anti-collision technology on its commuter rail network to comply with a federal mandate. The Red, Orange, and Blue lines have had safety systems for decades, the MBTA said.

The technology is long overdue, said Josh Ostroff, interim director of Transportation for Massachusetts an advocacy coalition. “As we saw with the Green Line crash, if we don’t provide the systems to safeguard riders, incidents are inevitable.”

The National Transportation Safety Board is currently investigating the July crash, its third such probe of a Green Line collision in 13 years. The trolley operator who struck the Green Line train from behind has been placed on paid administrative leave. The T hasn’t publicly identified the driver.


Federal transportation officials first recommended the MBTA install anti-collision technology on the Green Line in 2009, following two major crashes, one of which was fatal. The technology would essentially eliminate the possibility of driver error, and have the ability to halt speeding trolleys.

Investigators at the scene of a July 30 crash between two Green line T trains on Commonwealth Avenue.Barry Chin/Globe Staff/file

Since then, mounting evidence has highlighted the need for such a system. Between 2013 and last year, the MBTA led the nation in light-rail car derailments with the Green Line having more than twice as many incidents during that period as the San Francisco system, which had the second-highest tally, federal statistics show. More than half the trains weren’t carrying passengers when they derailed, the MBTA said.

Today, the solution that the MBTA has settled on is not what the NTSB recommended in 2009.

The NTSB sought a safety system known as positive train control, but the MBTA scrapped that idea in 2012, saying in part that it would cost $645 million to $721 million, a sum that could have covered the expense of replacing almost the entire bus fleet at the cash-strapped agency.

Ron Lindsey, an independent consultant who has designed positive train control systems, said the technology is good, but costly. Positive train control prevents accidents due to human errors, he said.


In its place, the MBTA has chosen to install a system that performs the same functions but uses different technology, said Joe Pesaturo, a spokesman.

The alternative system sends signal information to the trains, and has the power to brake a train if the operator doesn’t follow the signal. It has cameras that monitor the track and sends information to radar sensors, which can recognize potential obstacles in front of the train and warn the operator. If the operator doesn’t respond in time, the system automatically brakes, according to the MBTA.

But why has it taken the MBTA so long to settle on a safety system?

One reason appears to be the time it spent on investigating the technology. This effort began in 2008 after train operator Ter’rese Edmonds, 24, went through a stop signal at about 38 miles per hour and crashed into another trolley in Newton, killing her.

The NTSB concluded that Edmonds probably suffered from fatigue and may have momentarily fallen asleep, but also faulted the MBTA for not investing in safety technology.

While the NTSB was investigating this crash, a fatal commuter rail crash in Southern California led to the enactment of a federal law mandating positive train control on tracks used by freight and large passenger trains.

A train operator was killed in May 2008 in this crash in Newton. Suzanne Kreiter

The mandate didn’t apply to the Green Line, but in 2009 NTSB investigators were back in Boston after a train rear-ended another train near Government Center, injuring 49 people and causing nearly $10 million in damage. In that case, the NTSB faulted the train operator for texting at the time of the crash, but also noted that the Green Line still lacked the safety system.


Eric Gonzales, an associate professor of civil and environmental engineering at the University of Massachusetts Amherst, said the Green Line’s unique environment requires a different approach than commuter rail and the other subway lines.

The Green Line doesn’t have to worry about encountering a freight train on its tracks, but it does share parts of its route with street traffic.

The MBTA has long worried how safety technology would affect Green Line service. That line — really four lines that converge — traverses 23 miles underground and on the street. The system also runs more trains than the other subway lines — Green Line trains only carry two cars, instead of the six cars on other lines.

The T feared positive train control would keep trains spaced so far apart “as to significantly degrade service and capacity,” said Pesaturo, the MBTA spokesman.

In December 2012, the MBTA Board of Directors rejected a plan to install the technology on the Green Line and asked the T to come up with other options, Pesaturo said.

The NTSB voiced its displeasure and asked the T to reconsider, telling the T that its response was unacceptable.

“The urgency of this issue continues to be highlighted in other NTSB investigations, where we have repeatedly concluded that technological solutions have great potential to reduce the number of serious train accidents,” the board wrote the MBTA in July 2015.


A timeline provided by the T shows it took more than six years for the agency to identify an alternative and present it to the NTSB and the state Department of Public Utilities, which regulates the MBTA.

In May 2019, the T awarded a contract for the alternative safety system, which uses cameras and radar systems to detect non-train obstacles..

Professor Jason Rife, who leads Tufts University’s Mechanical Engineering Departmentsaid it makes sense to try camera and radar technologies on the Green Line.

“In concept, a radar [and] camera system is much more flexible, because it could prevent not only train-to-train collisions, but other types of collisions as well,” he wrote.

The T gave the green light to proceed with the project in January 2020 and equipment installation is planned to begin next year.

Sirman, the Green Line passenger, said learning about the delay in installing the safety technology may make him think twice about using the subway when he moves back to Boston next year.

But, he added, riding the trains is inevitable in Boston — to get to the supermarket, the airport, to see friends. “I can’t imagine not being on the T at all,“ he said.

Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her @lauracrimaldi. Elizabeth Koh can be reached at elizabeth.koh@globe.com. Follow her @elizabethrkoh.