Asleep at the controls: preventing injuries and loss by managing fatigue and shiftwork

May 09, 2014

By Ivan Szlapetis

falling asleepA recent video showing a Chicago subway train riding up an escalator after derailing at Chicago's O'Hare International Airport graphically depicts what can happen when overtired workers fall asleep on the job. Organizational factors may have contributed. Media reports indicate the driver was often assigned erratic schedules as a fill-in in for other employees, and had clocked lots of overtime.

Around the world fatigue contributes to thousands of preventable workplace incidents daily: many minor, some catastrophic. Transport Canada estimates that 20% of traffic fatalities result from fatigue-related impairment. Consider the possible impact of shiftwork and fatigue in these catastrophes:

  • Malaysian Airlines MH 370's last contact with Air Traffic Control - 1:20 am
  • Lac Megantic train derailment - 1:15 am
  • Bronx commuter train derailment - 7:22 am
  • Sunrise Propane explosion in Toronto - 3:50 am
  • Bhopal, India gas leak - 12:30 am
  • Chernobyl nuclear reactor explosion - 1:23 am

Certainly, shiftwork was not the only cause, but fatigue and disruptions to workers' biological clocks can impair memory, reaction time, judgement, and problem solving skills. Although the Bronx train derailed during daylight hours, early investigation findings suggest that the engineer may have nodded off at a critical point due to a recent shift schedule change, and a previously undiagnosed sleep disorder.

Everyone experiences an occasional sleepless night, and as we age the quantity and quality of our sleep tends to diminish. Fortunately, much can be done by employees, supervisors and business owners.

Fatigue prevention and mitigation options




  • If you fall asleep as soon as your head hits the pillow, you may be sleep deprived and not know it
  • Learn more about your sleep habits
  • Observe behaviour that suggests fatigue impairment
  • Monitor voluntary overtime to ensure reasonable time off between shifts
  • Track sleep and activity using a sleep log. Many who think a medical condition is affecting their sleep are actually limiting their sleep with poor habits
  • Review incident and injury statistics for possible time-of-day trends
  • Consider anonymous surveys of shiftworkers to compare the average length and quality of sleep for different shift cycles
  • Speak to your doctor and consider a referral to a sleep study for diagnosis and treatment
  • Learn about sleep hygiene, or good habits that promote sleep, such as creating a sleep routine, recording late-night TV programs instead of watching them live, and exercising at appropriate times
  • Use healthy strategies to increase alertness
  • Use safeguards to reduce injury risk due to lapses of attention or poor judgement
  • Adjust shift schedules and your environment to promote alertness
  • If the consequences of workers falling asleep are high, consider a fatigue risk management system, such as those developed for aviation
  • After setting realistic behaviour-based goals, identify habits you could change, and where you may need a new strategy
  • Keep in mind that habits are hard to change, especially if you have a partner with the same habits
  • Evaluate the physical, psychological and social impact of changes on your workers through observations and follow-up surveys. Keep in mind that younger and older workers may have different needs

Shortly after the Chicago subway incident, the Chicago Transit Authority committed to making some of the changes listed above. For instance:

  • setting a maximum 12 hours of train operating duty in any 14-hour time period
  • increasing minimum rest time between shifts from 8 to 10 hours
  • requiring train operators to take at least 1 day off in any 7-day period
  • limiting first-year train operators to 32 hours a week of actual train operation.

Ivan Szlapetis is a consulting services manager for WSPS and a certified ergonomist. WSPS ergonomic specialists can help you identify fatigue risks and solutions in your workplace. To speak with a WSPS consultant, call 1-877-494-WSPS (9777) or 905-614-1400.