Metro Crash May Exemplify Paradox of Human-Machine Interaction - washingtonpost.com

Greg Jamieson, an expert who studies human factors and engineering systems at the University of Toronto, said many automated systems explicitly tell human operators to disengage; they are designed to eliminate human "interference." After the previous fatal accident on Metro, in which a train overshot the Shady Grove station on an icy night, the National Transportation Safety Board found that the driver of the train had reported overshooting problems at earlier stops but was told not to interfere with the automated controls.

"The problem is when individuals start to overtrust or overrely or become complacent and put too much emphasis on the automation," Jamieson said. "In the Shady Grove accident, for a year before the accident, the transit authority had put in position a directive that you were not to drive the train in manual."