The Newton crash prompted the T to embark on a two-part strategy to inject technology into its traditional practice of training and testing drivers for alertness. It began a four-year, $460,000 trial of alarm systems and other technologies that fall short of full positive train control, using the 2½-mile route known as the Mattapan High-Speed Line as a laboratory.
But MBTA engineers say an alarm-style warning system would not be appropriate for the Green Line, which is why the T has also spent two years and $2.2 million on a study of what more sophisticated anticrash measures would look like for the Green Line.
Even during rush hour, Mattapan trolleys are spaced five minutes apart — rapid-fire by the standards of most light rail, the modern term for streetcar or trolley systems, but nothing compared with the Green Line.
That line — really four lines that converge — is the nation’s busiest light-rail system, moving 250,000 riders on busy weekdays and sending two- and three-car trains coursing through its underground core every 90 seconds at rush hour, and that’s just in one direction.
In that central subway section, where the four above-ground branches of the Green Line weave together, the vagaries of crowds getting on and off mean one train often catches up with another at a station before the lead train pulls away.
So an alarm meant to buzz or blink when trains get too close would activate routinely.
The project team studying safety technologies for the Green Line indicated as much last year in a presentation to the Department of Transportation board, meeting no objections. But the November crash injected a new urgency.
Some board members briefed at the Dec. 5 board meeting seemed taken aback by the project’s estimated cost and timeline, calling for cheaper, faster alternatives.
“My van has this little thing on the side mirrors that when a car comes up to me, it beeps and I pay attention,” board member Janice Loux said, visibly frustrated. “If there is something that will notify those guys that isn’t this nine-year, $750-million — put it on the things now!”
The consultant HNTB, working with MBTA engineers, surveyed anticrash technology makers and visited some of the world’s largest transit agencies, proposing three leading options. They also employed a computer model to simulate how those and other available technologies would affect station-to-station travel times as well as the waits between trains, producing two reports totaling 450 pages.
Their estimates for the cost included outfitting tracks, trains, and the T’s dispatching center with new technology but also investing in improvements to make up for the lost time if Green Line trips are spread apart for safety. Some changes to gain speed are simple — such as adding an extra employee toilet at North Station. Others are as complex as rebuilding track curves and tunnel sections.
But the team only got a few slides into their presentation to the board when they were rebuked for not proposing cheaper alternatives that could be deployed sooner.
Loux, a labor leader, said alarms should be installed even if they go off so often that drivers tune them out. “I want it on the trains, or I’ll challenge you, I’ll go out and find it myself,” she said.
Board member Ferdinand Alvaro, a corporate lawyer, told officials to put in more work. “Before this board makes any kind of a decision on a three-quarters-of-a-billion-dollar project, we ought to know what the alternatives are,” he said.
Davey said the team will explore lower-cost options as an interim measure while developing plans for a more sophisticated — albeit expensive — automated safety system, with no deadline specified.
“The board has articulated that safety upgrades on the Green Line have to be a priority,” he said. “One accident on any line, bus, or subway, is too many.”
Eric Moskowitz can be reached at email@example.com.