There are multiple reasons why metros are particularly affected by human failures, including operations and/or maintenance occurring 24-hours a day, human judgement involved in multiple safety critical situations, and the potential for unpredictable overtime. Across COMET metros, human failure caused the majority of collisions and derailments. Miscommunications and multi-tasking are considered the top two most influential factors on human failures.
The study focused on active human failures that directly lead to incidents. Active failures are categorised into errors and violations, which can be further sub-categorised by the underlying motive, intention, and/or frequency. Understanding active failure types supports greater understanding of the root causes of failure.
The study reviewed strategies for preventing human failure including process, environment, and people-based solutions. One example for preventing human error is assessing fitness for duty among train drivers. Half of metros reported use of a checklist or declaration, with some metros use technology to address fatigue including monitoring attentiveness and encouraging sufficient rest for employees before their shift. While many of these measures are focused on train drivers, increasing automation within metros means that such measures are becoming just as important for OCC staff. Opportunity areas for metros to reduce operational risk of human failures are discussed, supported by good practices and future initiatives conducted by COMET metros.