However , claim that operator was taking sleep aid leads to conjecture . Transportation board criticized for failing to check for sleep disorders . The safety board , completing a 14-month investigation , faulted operator Ter'rese Edmonds for ignoring a red signal along the tracks but directed harsh criticism at the Massachusetts Bay Transportation Authority which operates the train system . Board also criticized lack of systems to prevent trains from using same stretch of track .
However , claim that operator was taking sleep aid leads to conjecture . Transportation board criticized for failing to check for sleep disorders . Board also criticized lack of systems to prevent trains from using same stretch of track .