Inquiry faults T on safety measures

“If technology exists - and it exists on the other lines - why would the Green Line not have everything possible that is going to prevent the accidents from happening?’’ Mark V. Rosenker, acting chairman of the National Transportation Safety Board, said during a hearing in Washington, D.C., to discuss the 2008 crash near Waban station.

“I don’t understand that, as an operator,’’ Rosenker said. “I just don’t.’’

MBTA drivers on the problem-plagued transit line, the country’s oldest, have long called for such an automated system, which could prevent trolleys from coming too close to one another and stop them if necessary.

After a 14-month investigation, the NTSB also concluded the driver who died in the crash probably suffered from fatigue and may have fallen asleep momentarily.

The seven recommendations included a call for US transit agencies to establish a better system for medical screening of sleep problems in operators, each of whom is responsible for the lives of thousands of commuters each day.

MBTA general manager Daniel A. Grabauskas and state Transportation Secretary James A. Aloisi Jr., chairman of the T board, declined requests for interviews yesterday.

Other officials at the Massachusetts Bay Transportation Authority defended the system’s safety record and pointed to a number of measures the agency has taken since last year’s crash, including a more frequent and formal system to observe drivers’ speeds and safety compliance on the tracks.

The NTSB put forward yesterday’s recommendation about the need for an automatic operating system despite an ongoing investigation into a deadly crash in Washington, D.C., in June that appears to have stemmed from a failure in that transit agency’s computerized system.

Though the T in Massachusetts has taken preliminary steps toward building an automated train control system for the Green Line in recent months, the agency has been slow to embrace the technology and remains uncommitted about retrofitting the trains, despite another major Green Line accident this May that raised similar questions about the line’s lack of fail-safe technology.

Managers of the financially strained authority have cited the cost and concerns that the automated system, which relies upon keeping trolleys a certain distance apart, would prevent the Green Line from running efficiently through downtown stations.

The Green Line presents more challenges than the Blue, Red, or Orange lines, which are more traditional heavy-rail subway lines. The Green Line is a light-rail trolley system that runs more cars through central downtown stations and also intermingles with street traffic on all but one of its above-ground branches.

After the more recent crash renewed focus on the line’s technology, Grabauskas called the issue a distraction from what he characterized as the central cause of the crash, a trolley operator distracted by a cellphone.

But NTSB board members said yesterday that an automated system would provide an added layer of protection against operator errors, including the one that caused the 2008 crash.

“I scratch my head at the fact that they didn’t have’’ an automated system on the Green Line, Rosenker said. “If, in fact, [it]had been implemented, I don’t believe we’d be in here discussing this today.’’

Investigators say they could not fully explain why, on May 28, 2008, Ter’rese Edmonds, 24, the operator of the Green Line train, blew through a red light at 38 miles per hour, failing to engage the brakes during the seven seconds in which the train in front of her would have been visible. She died after her vehicle struck the second train, which had been stopped at a red signal along an idyllic stretch of track next to Brae Burn Country Club.

The NTSB concluded yesterday Edmonds may have experienced a “microsleep,’’ based on investigators’ belief that she was at high risk of undiagnosed sleep apnea. She was overweight, and a toxicology report showed the presence of an over-the-counter sleep aid in her urine.

Investigators do not believe the sleep aid would have impaired her ability to run the train, because it was not in her blood stream at the time of the crash.

There was some debate among board members about how definitively they could pinpoint fatigue as a problem, given that Edmonds had a predictable schedule with moderate hours and plenty of time for sleep between shifts.

Board members were quick to point out that, regardless of that finding, Edmonds was a highly praised employee known for a conscientious attitude.

Work schedule was not cited as an issue in Edmonds’s case, but the T nonetheless changed one of its policies last month, lengthening the minimum time between shifts from six hours to 10 hours.

Edmonds’ father, Terry Jones, said he doubted his daughter had a sleep problem.

“She didn’t have a hard time sleeping at all, not at all,’’ Jones said. “I’ve seen her every day that she worked, dropped her off at work sometimes. She wasn’t tired at all. . . . She just missed. That’s the only thing I can say.’’

In recent weeks, the T has begun the process of finding an engineering consultant to examine an automated train control system on the Green Line, which could remotely restrict train speeds or prevent trains from getting too close to one another.

At the same time, the agency plans to test a low-cost collision warning system on the Mattapan trolley system, which could be used on the Green Line if it proves effective.

The technology “keeps evolving,’’ said MBTA spokesman Joe Pesaturo. “That’s why we’re bringing in the experts that will examine all the technology available today . . . and make a recommendation.’’

The Globe reported in May that the T had fallen months behind its internal schedule in hiring a consultant, partly because of its ongoing debt and deficit problems.

Estimates for building a first-class train control system top $300 million, though it remains possible the T could retrofit the Green Line with something cheaper and less sophisticated and take advantage of federal funds often available for large-scale safety upgrades.

But even systems advertised as fail-safe offer no guarantees, as appears to be the case in Washington.

Peter Knudson, an NTSB spokesman, said the agency has yet to draw conclusions in that accident, but is certain the T would have benefited from an automated crash prevention system.

“In this accident, we are quite confident that had there been a redundant system, it would have prevented the accident,’’ said Knudson.

Noah Bierman can be reached at nbierman@globe.com.