Accounting for sleep disorders in highway safety

Praveen Edara
Praveen Edara, chair of the Department of Civil and Environmental Engineering

People with shift work sleep disorder (SWSD) are three times more likely to crash or be in a near-crash than people without that condition. That’s the take-away from a study on accident causes and sleep disorders conducted by civil and environmental engineering (CEE) professors Praveen Edara and Carlos Sun. In addition, they found that people with sleep apnea or insomnia had a 30% greater chance of crashing or nearly crashing.

“We’re interested in anything that has to do with road crashes,” Edara said. “Our interest is more in causal factors for different crashes, and we had access to a unique data set that let us look at health-related data and how sleep affects crashes.”

This research expands upon previous efforts in drowsy driving research. The team had access to real-world crash and near-crash data collected through the second Strategic Highway Research Program (SHRP 2).

“We had naturalistic driving study (NDS) data from six states and close to 2,000 events,” Edara said. “In the past, researchers have studied this primarily in controlled environments, test tracks and driving simulators, but not many utilized observed crash data. Ours is one of the few studies that used this unique SHRP 2 NDS dataset to better understand how sleep disorders affect safety.”

Carlos Sun
Professor Carlos Sun, director of Construction Management Programs

According to the National Highway Transportation Safety Administration (NHTSA), 697 deaths occurred on highways because of drowsy-driving-related crashes in 2019. And in 2017, there were approximately 91,000 crashes involving drowsy drivers, according to police reports.

To help curb these accidents and fatalities, Edara has several suggestions, such as using ridesharing companies and public transportation, and creating more rest areas along major highways. Governments can also implement more rules, similar to what is in place for commercial truck drivers.

“The NTSB (National Transportation Safety Board), the agency that investigates major accidents, creates an annual list of most-wanted safety improvements, and last year’s list included ‘Screening and Treating of Sleep Apnea’ in their top 10. If you are a commercial truck driver, there are laws that the NTSB requires shipping companies implement a mandatory screening and treatment program for sleep disorders.”

The National Sleep Foundation defines SWSD as a chronic condition that is directly related to a person’s work schedule. It primarily affects people who work night, early morning, and rotating shifts for their jobs. The disorder may cause insomnia when workers attempt to sleep and/or excessive sleepiness while they are at work.

As for potential further research, Edara wants to partner with public health and medical professionals who specialize in sleep disorders. This would allow him to jointly explore this subject area in greater detail and develop engineering and behavioral countermeasures.

Edara serves as chair of the civil and environmental engineering department at the University of Missouri. He is a registered Professional Engineer in Missouri and a Certified Professional Traffic Operations Engineer (PTOE™). Sun is director of construction management programs in CEE and is also a registered Missouri Professional Engineer.

Learn more about civil engineering at the University of Missouri.

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