A methodology for the analysis of SPAD

Technology Implications of a Cognitive Task Analysis for Locomotive Engineers

“…Operators may respond to poorly designed audio alerts automatically without fully processing their meaning, thus defeating their purpose (Pasquini, et al, 2004). This is consistent with an extensive body of human factors literature that indicates that individuals are likely to ignore alarms when a high false alarm rate exists (e.g., Getty et al, 1995).…”

“…A recent analysis of signals passed at danger (SPAD) in Italian railways suggests that computerized systems intended to provide in-cab alerts of upcoming stop signals, if poorly designed, can fail to serve their intended alerting function (Pasquini, Rizzo, and Save, 2004). In the case examined by Pasquini, et al (2004), a locomotive engineer missed a stop signal in spite of an in-cab display system that provided an auditory warning of upcoming stop signals and required an explicit acknowledgement of the alert (via a button push).…”

“…In the case examined by Pasquini, et al (2004), a locomotive engineer missed a stop signal in spite of an in-cab display system that provided an auditory warning of upcoming stop signals and required an explicit acknowledgement of the alert (via a button push). The analysis conducted by Pasquini showed that, because of the way the alert system was designed, it promoted a tendency to automatically press the acknowledgement button when the alert came on without actually processing the alert message.…”

“…If the PTC display is placed in a location so that only the locomotive engineer can see the display, it reduces the ability of the second individual in the cab to provide a redundancy check. Pasquini, et al (2004), reviewing an Italian cab signal system, reported that the location of the cab signal interface did not allow the second locomotive engineer in the cab to read off the alert messages, thus reducing his or her ability to detect when a locomotive engineer was about to violate a signal. A similar issue was raised during the interviews with locomotive engineers and conductors regarding the CBTM system.…”

Rail human factors: Past, present and future

“…More recently we have certainly seen more sophisticated examinations of SPADs (e.g. Pasquini et al, 2004;Turner et al, 2003), and tools to identify the risk of SPADs at different signals (Holywell, 2005;Lowe and Turner, 2005). Related to this is research into the use of vigilance devices and reminder appliances (e.g.…”