In June 2009, a Washington Metropolitan Area Transit Authority (WMATA aka DC Metro) Red Line subway train traveling at a high rate of speed rear-ended a stationary subway train, killing nine people including the train's operator, with 52 injured passengers sent to the area hospitals. At the time, the Washington Post stated that given Metro's automated safety systems the crash was supposed to be "impossible."
In July of 2010, the National Transportation Safety Board (NTSB) concluded that the probable cause of the collision was
"... a failure of the track circuit modules that caused the automatic train control (ATC) system to lose detection of one train, allowing a second train to strike it from the rear. The NTSB also cited WMATA for its failure to ensure that a verification test developed after a 2005 incident near Rosslyn station was used system wide. This test would have identified the faulty track circuit before the accident."
In other words, the accident was attributable to not just faulty equipment but also a faulty safety culture within the DC Metro organization that essentially created a situation where an accident was inevitable.
On Tuesday, the Washington Examinerreported that all the parties to the accident—DC Metro which managed, operated and monitored train operations; Alstom Signaling and Ansaldo STS USA, which supplied components that were part of Metro train control and detection system; and ARINC, which supplied the software that monitored the movement of trains—are not contesting their liability in the crash.
This is the first time that DC Metro publicly admitted responsibility for the crash, the Examiner says.
The NTSB recommended a number of safety improvements to the DC Metro, which, to its credit, it has been implementing at a cost of over $1 billion. It will still be a few more years, however, before all the upgraded safety equipment is in place so that train operations are returned to automatic control from their current manual operation.
For a full list of blog posts on the crash and the NTSB's investigation of it, go to the search box at the top of the page, specify "blogs," and enter "DC Metro."
Robert N. Charette is a Contributing Editor to IEEE Spectrum and an acknowledged international authority on information technology and systems risk management. A self-described “risk ecologist,” he is interested in the intersections of business, political, technological, and societal risks. Charette is an award-winning author of multiple books and numerous articles on the subjects of risk management, project and program management, innovation, and entrepreneurship. A Life Senior Member of the IEEE, Charette was a recipient of the IEEE Computer Society’s Golden Core Award in 2008.