Management & Operations

NTSB: Fatigue, lack of PTC caused trolley crash

Posted on July 14, 2009

On Tuesday, the National Transportation Safety Board (NTSB) determined that the two-train collision on the Massachusetts Bay Transportation Authority (MBTA) Green Line last year occurred as a result of the trolley operator's failure to obey a signal indication, likely because she became disengaged from her environment consistent with experiencing an episode of micro-sleep.


The lack of a positive train control system, which would have intervened to stop the train and prevented the collision, was cited as a contributing factor.


At 5:51 p.m. EDT, on May 28, 2008, an MBTA Green Line train, traveling westbound at about 38 mph, struck the rear of another westbound Green Line train, which had stopped for a red signal. The operator of the striking train was killed; three other crewmembers sustained minor injuries. Of the 185 to 200 passengers who were on the two trains at the time of the collision, four sustained minor injuries and one was seriously injured. Total damages were estimated to be about $8.6 million.


Post-accident toxicological testing indicated that the operator of the striking train had recently taken the drug doxylamine, commonly found in sleep aids, suggesting that she had trouble sleeping during at least one of the nights leading up to the accident. In addition, the operator had a high body mass index (BMI), which is closely correlated with a higher risk for sleep apnea, increasing the likelihood of a fatigued condition during waking hours.


"Again, we've seen a situation where a positive train control system could have prevented a tragic accident," said NTSB Acting Chairman Mark V. Rosenker. "We know that because operators or equipment sometimes fail, redundancies like PTC systems can be the difference between a fatal accident and an incident report. And this is why we feel so strongly that transit systems like MBTA's should have that crucial extra layer of safety that a PTC system provides."


Because the NTSB concluded that the accident could have been prevented had the MBTA been equipped with a positive train control system, the NTSB recommended to the Federal Transit Administration (FTA) that the agency facilitate the development and implementation of positive train control systems for rail transit systems nationwide.


In addition, the NTSB recommended to the FTA that they develop and disseminate guidance for operators, transit authorities and physicians regarding the identification and treatment of individuals at high risk for obstructive sleep apnea and other sleep disorders.


The NTSB recommended to MBTA that train operators be required to notify fellow crewmembers when a restrictive signal is encountered and the intended means of complying with the restriction.


A summary of the findings including the Board's report is available on the NTSB's Website at


The entire accident docket is available at

View comments or post a comment on this story. (0 Comments)

More News

SORTA to sell advertising to pay for bus benches

In a separate ordinance, the city agreed to stop removing currently illegal benches at some stops unless they are unsafe.

Future for connected cars is promising, obstacles remain: study

Obstacles include privacy and security concerns, to a lack of infrastructure and the need for a legislative framework.

Caltrain begins courtesy campaign via social media

The campaign, called “Caltrain Manners,” is the result of a recent online survey, where passengers were asked what annoyed them most about their fellow riders. Caltrain tallied the results to determine the three worst passenger gaffes.

Sacramento RT receives state certification for bus apprenticeship program

Having trained and qualified mechanics is critical to RT’s mission of providing reliable bus service to the Sacramento region.

Community Transit programs removed 370K drive-alone trips in 2016

Choice Connections and Curb the Congestion target large employers and most-congested corridors, and recognize individuals who use transportation options.

See More News

Post a Comment

Post Comment

Comments (0)

More From The World's Largest Fleet Publisher

Automotive Fleet

The Car and truck fleet and leasing management magazine

Business Fleet

managing 10-50 company vehicles

Fleet Financials

Executive vehicle management

Government Fleet

managing public sector vehicles & equipment


Work Truck Magazine

The number 1 resource for vocational truck fleets

Schoolbus Fleet

Serving school transportation professionals in the U.S. and Canada

LCT Magazine

Global Resource For Limousine and Bus Transportation

Please sign in or register to .    Close