The National Transportation Safety Board (NTSB) has made nine recommendations to the Washington Metropolitan Area Transit Authority (WMATA, ‘Metro’), six of them considered ‘urgent’, in the aftermath of the June collision that killed nine.
The recommendations relate to the automatic train detection systems that were not properly designed and do not include any redundancy whatsoever. The NTSB has not yet officially identified the cause of the deadly collision, but it is believed to be related to a single failure in the Automatic Train Control (ATC)/Automatic Train Protection (ATP) systems. First-year engineering students are generally aware that it is a dangerous practice to design ‘fail safe’ safety systems without an independent backup system, and other rail systems similar to Metro (such as the San Francisco BART system) implemented redundant backups decades ago.
Metro has a history of blithely ignoring urgent NTSB recommendations, so I have no reason to believe that these new recommendations will be followed promptly by our wayward transit system. Following a collision in 2004 (which, thankfully, resulted in no deaths) the NTSB recommended that Metro remove its older ‘1000 series’ trains from service because they did not hold up well in accidents. Metro failed to do so. There is a good chance that, had Metro appropriately followed NTSB recommendations, the June collision would not have been so severe. All of those killed had been riding in a ‘1000 series’ car that should not have still been in service.