Commercial driver fatigue contributes to between 10 and 20 percent of the roughly 4,000 deaths caused by truck and bus crashes on U.S. highways each year, yet carriers and safety regulators still struggle with ways to mitigate the risk of deadly accidents that could involve tired drivers, according to a report from the National Academy of Sciences (NAS).

The report, issued yesterday and funded by the Department of Transportation (DOT), said the links among inadequate sleep, diminished driver alertness, and increased crash risk have been established. It is also well known that the stresses associated with the work, namely irregular schedules and economic pressures, place drivers at a higher risk of insufficient sleep, NAS said. However, there has been little progress in connecting all the dots to help reduce the chances fatigued drivers will put themselves and others in harm's way on the road, NAS said.

Work in this area is further complicated by the difficulty of objectively measuring driver fatigue, the invasive nature of capturing the amount and quality of drivers' sleep, and factors besides fatigue that may have caused a crash, NAS said. Though plenty of driver health and wellness data has been gathered on drivers who work for large truck fleets, significantly less information is available on drivers who work for small carriers, and, in particular, owner-operators, according to the report.

The Academy recommended that either the Department of Health and Human Services (HHS) or DOT, or the agencies working together, fund and conduct an ongoing survey to track changes in drivers' health status over time, as well as the factors likely to have triggered those changes.

The Federal Motor Carrier Safety Administration (FMCSA), the subagency of DOT that oversees truck and bus safety, declined comment on the NAS findings. As part of a Congressional mandate under last year's five-year transport spending law, FMCSA on Monday commissioned NAS to study the effectiveness of the seven metrics FMCSA has used to identify high-risk carriers under its Compliance, Safety, Accountability (CSA) carrier-grading program. An FMCSA spokesman said today's NAS report and its action on Monday are unrelated.

Also on Monday, FMCSA restored to its web site the raw data used to compile carrier safety scores under CSA. Congress allowed the agency to keep the data available for public view, although it ordered the comparative safety scores of carriers to be removed.

Driver fatigue has long been a corollary to the often-contentious debate over the length of time a driver can be on the job, behind the wheel, and at rest. However, the American Trucking Associations (ATA), which represents mostly large fleets, said in a statement today that the "singular focus on (driver) hours-of-service rules as a 'silver bullet' countermeasure to address fatigue is ineffective."

The group acknowledged that it makes sense for NAS to "study the many factors" that may have a relation to crashes, such as how drivers choose to spend off-duty time that should be used to rest. But it added that the focus "should not be on crashes where fatigue is merely present, but on those resulting from fatigue."

The Owner Operator Independent Drivers Association (OOIDA), which represents owner operators, did not have a comment at press time.