RISKS-LIST: Risks-Forum Digest Monday 13 May 1996 Volume 18 : Issue 11 FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS (comp.risks) ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator ------------------------------ Date: Fri, 10 May 1996 09:19:35 -0500 From: JEREMY J EPSTEIN Subject: Massive failure of Washington DC traffic lights According to the 9 May 1996 *Washington Post*, most traffic lights in downtown Washington D.C. went onto their weekend pattern (typical: 15 seconds of green per light), rather than their rush hour pattern (typical: 50 seconds of green per light). This occurred during the Wednesday (8 May) morning rush hour. The problem was reportedly caused by a new version of software installed in the central system that controls all of the traffic lights, providing timing (so lights turn green in sequence). The result was mile-long traffic jams. One woman reported that her 35-minute commute turned into 75 minutes, due to the overloaded streets. By the afternoon rush hour, the software glitch had been "fixed". It wasn't clear whether that meant they reloaded the old software or fixed the bug. Some might consider this a risk of computer controlled systems, and others might consider it a substantial increase in the nation's productivity: think of all the lawyers and congresscritters who couldn't get to work! ------------------------------