The incident caused severe delays on the Blue Line.
The T says it’s better prepared to handle the extreme weather that caused widespread delays throughout the public transportation system last year and led to a public outcry for fixes.
MBTA officials are trying to find ways to cut costs for the Green Line Extension, which is planned to go from Cambridge into Somerville and Medford.
Gov. Charlie Baker and state transportation officials are trying to figure out how a Red Line train was able to leave Braintree Station Thursday morning with about 50 passengers on board and no operator.