This morning at 5:09 a.m., Muni Metro service experienced an infrastructure equipment failure at the turnback past Embarcadero station. Trains at this time were operating in automatic, but the reduced capacity at the turnaround generated congestion between Van Ness and Embarcadero stations.

Shortly after 9:00 a.m., we also experienced a central computer failure of our Automated Train Control System (ATCS) which caused a loss of communication between all trains in the subway. For safety, non-communicating trains operate at less than half the speed as automatic trains. This ensures our customers’ safety but reduces the number of trains the subway can handle at a time whenever there is a communications problem. The restart of the computer only takes about five minutes, but we did not re-establish communications with all of our trains until 10:10 a.m. Unfortunately, due to the design of our subway’s train control system, trains can only reestablish communications at specific locations with the system, which means it takes over an hour to process the roughly 40 trains that were in the subway at the time. Our signal crews worked diligently to fix the infrastructure issue and our control center staff restarted the central computer. Additionally, parking control officers, station agents and transit fare inspectors directed riders to bus shuttles throughout the system.

We understand our city’s needs for a world-class and modern transportation system and we are committed to doing everything we can to replace and expand our fleet and explore options to replace our aging infrastructure that is at the root of many of these delays. We share your frustrations. Our crews are investigating to determine if the two failures are linked. We are sharing all possible data on today’s incident with the ATCS manufacturer, to understand the cause of the problem and once the cause is known, we will take steps to minimize the chance of reoccurrence. We sincerely apologize for the delay and are working on immediate solutions.