Study Finds Additional Research Needed to Better Understand Driver Fatigue
This story appears in the March 14 print edition of Transport Topics.
While there is some evidence that fatigue among truck drivers increases the risk of crashes, questions remain about effective ways to minimize that risk, according to a new report from the National Academies of Sciences, Engineering and Medicine.
The report, requested by the Federal Motor Carrier Safety Administration, recommended several improvements in data and research methods used by the agency to support a more comprehensive understanding of the relationships between fatigue, highway safety and long-term health.
Further study of driver fatigue is critical, since from 10% to 20% of the approximately 4,000 fatalities due to truck and bus crashes occur each year involve fatigue, according to the panel of experts involved in the report.
“The FMCSA has several policies and programs to improve highway safety involving large trucks and buses that are based on the current scientific understanding of operator fatigue, its causes, and its consequences,” the March 10 report read.
One of those policies, hours-of-service regulations for truck and bus drivers, limits the maximum numberof hours drivers can work based on the assumption that drivers will have enough time to obtain adequate sleep between shifts, and therefore will be more alert while driving, the report said. “However, HOS rules can only limit hours spent working; they cannot require drivers to get adequate sleep and rest while off duty.”
Rob Abbott, vice president of safety policy for American Trucking Associations, said that focusing on hours-of-service rules as a “silver bullet” countermeasure to address fatigue is ineffective.
“It is appropriate for the National Academies to study the many factors that can impact such crashes, such as how drivers choose to spend off-duty time that should be used to rest,” Abbott said. “The focus, however, should not be on crashes where fatigue is merely present, but on those resulting from fatigue.”
An FMCSA spokesman declined comment on the report.
The study noted that drivers face stresses not only due to irregular schedules and economic pressures. They also are at substantial risk for insufficient sleep and the development of several chronic health issues, including obstructive sleep apnea, hypertension, cardiovascular disease, adult-onset diabetes and other conditions commonly associated with obesity.
The report also concluded that although efforts have been made to assess the percentage of crashes, or fatal crashes, in which fatigue played a key role, “assessment of whether fatigue is a causal factor in a crash is extremely difficult and likely to suffer from substantial error.”
In addition, the panel found that substantial data gaps limit understanding of the factors that affect the health and wellness of CMV drivers.
“Although considerable data are collected on drivers who work for large carriers, much less information is available on those who work for small carriers, especially independent owner-operators,” the report said.
The researchers also studied the potential of using various onboard technologies, but concluded that despite almost three decades of research on technological innovations for detecting driver fatigue in near real-time “operational strategies for their use are still in the early phases of understanding and application.”
“FMCSA should support research aimed at better understanding the factors associated with driver behavior related to fatigue and sleep deficiency, including what motivates drivers’ decisions about whether to continue driving when they feel fatigued,” the study said.
The report said that drinking coffee and other caffeine products can provide temporary relief from driver drowsiness, and rumble strips can serve to alert sleepy drivers who are drifting out of their lanes.
But it concluded “there is no biological substitute for sufficient sleep: The only way to alleviate driver fatigue is to obtain an adequate quality and quantity of sleep.”
The panel also pointed to FMCSA challenges in diagnosing drivers who either have or are prime candidates for obstructive sleep apnea, a clear threat to highway safety as well as long-term driver health.
“The absence of specific guidance to certified medical examiners on assessing CMV drivers for OSA presents challenges for employers who rely on the medical examiner to make determinations but who find that inconsistent criteria are used,” the study said.
The report said that FMCSA issued a bulletin to medical examiners and training associations early last year stating that examiners should use “current best practice” in determining which drivers should have objective testing and offering some considerations for addressing OSA, but noted that the agency has no specific standards.
