Multiple shift work is a constant in the construction industry, caused by either demanding deadlines or government requirements (highway work in particular). A study released at the turn of the year from Oregon State University found a direct correlation between shift work sleep disruption and worker safety.

This study, published in the December 2020/January 2021 issue of the Journal of Occupational Health, found that the frequency of injuries increased in each of the first four hours of a shift and peaked during the fourth hour. Workers who started their shift in the evening or at night were more likely to experience injuries and suffer more severe injuries than daytime workers, based on lost workdays and medical costs.

The investigators from the Corvallis campus used data from the Workers’ Compensation Division of the Oregon Department of Consumer and Business Services. The information allowed them to conclude that medical costs and lost workdays varied depending on the time of injury. For work shifts starting during evening and night time, the injuries were more severe. Similarly, injuries during evening and night time had higher average medical costs and more average lost workdays.

“Drowsy Driving” More Than An Innocuous Phrase

According to current figures from the National Highway Traffic Safety Administration, it’s a deadly serious problem. An estimated 1,550 deaths, 71,000 injuries, and $12.5 billion in monetary losses are due to drowsy drivers. Some of those are sleep deprived construction workers coming to and from their night shift job sites 

Following on the Oregon study’s heels are research findings at the University of Missouri College of Engineering, which discovered that drivers who experience shift work sleep disorder are three times more likely to be involved in a vehicle crash. 

The MU team also examined the relationship between vehicle crashes and two other sleep disorders, sleep apnea and insomnia.

The study, Sleep Disorders and Risk Of Traffic Crashes: A Naturalistic Driving Study Analysis, was published in Safety Science (formerly known as Journal of Occupational Accidents) in March. Co-authors were Carlos Sun in the MU College of Engineering and Nipjyoti Bharadwaj with the Federal Highway Administration.

“This discovery has many major implications, including the need to identify engineering countermeasures to help prevent these crashes from happening,” said Praveen Edara, department chair and professor of civil and environmental engineering. “Such measures can include the availability of highway rest areas, roadside and in-vehicle messaging to improve a driver’s attention, and how to encourage drivers who may have a late-night work shift to take other modes of transportation, including public transit or ride-share services.”

The report used data collected from a real-world driving study for the second Strategic Highway Research Program established by the U.S. Congress.

Edara said he was surprised to see shift work sleep disorder increase the risk of a traffic crash by nearly 300 percent compared to sleep apnea and insomnia, which increased the risk of a crash by approximately 30 percent. 

“In the past, researchers have studied sleep disorders primarily in a controlled environment, using test-tracks and driving simulators,” Edara said. “Our study goes a step further by using observed crash and near-crash data from approximately 2,000 events occurring in six U.S. states. We’ve known for a while now that sleep disorders increase crash risk. Still, here we can quantify that risk using real-world crash data while accounting for confounding variables such as roadway and traffic characteristics.”

As the academics continue to drill down on this topic, you can be sure that it will filter into the halls of Congress and state legislatures and reverberate into the regulatory agencies. It’s enough to disturb anybody’s sleep patterns.