ARLINGTON, Va. – The DOT’s justification for changing the hours of service rules continues to crumble, according to the American Trucking Associations.

A leading sleep expert whose scientific studies were used by the Federal Motor Carrier Safety Administration to underpin the proposed changes, says the government agency misapplied those findings and misused his research.

Dr. Francesco Cappuccio, a physician and researcher at Warwick Medical School in the UK released an analysis of the FMCSA’s use of his work.

Cappuccio — who the ATA says has reviewed 16 published studies on the effect of sleep duration on mortality and co-authored a 2007 study that the FMCSA leaned on most heavily to support its proposal – says many of the agency’s interpretations are flawed, including the claim that short projected increases in sleep could generate roughly $690 million in annual health benefits for drivers.

He concludes that the FMCSA cannot use his studies to quantify benefits to justify changes to the driving time limit or shrinking the workday window by one hour.

"The current evidence … do not support the conclusions of the FMCSA that a small increase in sleep duration of a few minutes following the HOS options proposed, particularly in the groups with baseline daily sleep (greater than) 6 hours per night, is likely to decrease the mortality risk of individuals or groups," he wrote.

He also concluded that there is no evidence to prove that, "without additional measures, a simple reduction in work hours will result in increased sleep time."

"It is premature to address specific policy changes on the basis of the published relationships between sleep time and mortality risk in epidemiological studies of general population samples. Specific new research needs to address the gap in evidence to support future policies."

As well, Cappuccio questioned FMCSA’s assumption that if drivers worked fewer hours they would actually use the extra time (or significant part of it) to sleep. "This assumption is unsupported and there are studies indicating that this is not necessarily the case, and that other initiatives ought to be taken in order to direct the off-duty time to sleep."

In its Regulatory Impact Analysis, the FMCSA claimed that  there is a "growing scientific consensus" that the amount of sleep a person gets is connected to health.

While much of Cappuccio’s research implies such a connection in people who are routinely and severely sleep deprived (he also says too much sleep could be harmful), he is clearly suggesting here that is not the case with the average driver currently and FMCSA’s specific changes would have virtually no impact on health. 

The ATA, which asked Cappuccio to review the FMCSA’s methodology, says his report reinforces the group’s claim that FMCSA proposed changes based on politics, not science.

"The ATA has said since the outset that policy changes of this scope need to be based on sound science and research, not political pressure and unproven theories," ATA President and CEO Bill Graves said in a statement. "The fact that this prominent physician and sleep researcher clearly states the agency is wrong to use his and others work in this way clearly exposes the serious flaws in this proposal."