Transit lines and railroads that use the same signal system that failed to detect a stopped train in the area of a deadly Washington crash should check them to make sure they are working correctly, a federal safety board urged Tuesday.
The National Transportation Safety Board said it was not ready to say what caused the June 22 crash that killed nine and injured 70 when a train hit another one stopped on the tracks. However, it issued nine safety recommendations, including six deemed urgent, to the Washington Metropolitan Area Transit Authority and others.
On the Metro line, each track circuit uses two modules to communicate. The NTSB said tests after the crash showed the modules communicated without checking with the rails, causing the circuit to lose its ability to detect the stopped train.
"Our findings so far indicate a pressing need to issue these recommendations to immediately address safety glitches we have found that could lead to another tragic accident on WMATA or another transit or rail system," NTSB Chairman Deborah A.P. Hersman said in a statement.
The NTSB had said previously that equipment that is supposed to detect stopped trains failed periodically in the days leading up to the crash. Metro also said the system failed to detect trains during tests after the crash.
The board recommended that Metro and Alstom Signaling, which made the track circuit modules, work together to eliminate the problems that could affect the safe performance of the system. It also said Metro should develop a regular testing program.
It asked federal departments to advise all rail transit operators and railroads that use audio frequency track circuits about the findings from the accident investigation.
The NTSB has requested responses from each of the rail agencies within 30 days on the urgent recommendations, with steps they have taken or plan to take.
