Can you say "circadian rhythm?" Featured

10:02am EDT July 22, 2002

Pitt Ohio Express Inc. truck driver Dana Scarff isn't unlike most of his tough professional breed. He drinks lots of coffee, loves to tell stories and laughs with the understated, rough-edged candor and cynicism of a veteran midnight hauler. Typical truck driver.

That is, until he starts talking about his circadian rhythms.

You may not hear him talk to his trucking buddies on the CB at night about this scientific phenomenon, but Pitt Ohio has made sure Scarff and his driver colleagues not only understand the terminology, but also use the knowledge to make them safer drivers. In fact, the Strip District-based trucking firm is so determined to stay at the leading edge of circadian-based study and safety that, for the past two years, it has allowed its drivers to become guinea pigs for a massive breakthrough study by research scientists from Carnegie Mellon University and the University of Pennsylvania.

The outcome, all participating parties hope, will be a new technology designed to both alert commercial drivers when their fatigue leads to drowsiness and, ultimately, force them to pull off the road and rest.

"Just being associated with this study carries us a long way," says Ronald Uriah, vice president of safety at Pitt Ohio. "This could be one of the most prominent technology advancements in many years, and we're on the cutting edge of this research. We hope to apply it to ourselves to enhance our operation. We never want to rest on our laurels."

So what, exactly, is a circadian rhythm? The scientific theory says our bodies function naturally according to cycles of energy driven by light and darkness. We're most energetic, the theory holds, during periods of daylight, when the sun feeds us with its energy. Our bodies naturally slow down within a certain cycle of time at night, a period known as a circadian trough. Understanding those peaks and troughs, trucking officials and scientists contend, is half the battle when it comes to improved safety.

Scientists have been studying circadian rhythms for years, particularly as they affect shift workers and others-including Pitt Ohio drivers-who have to work the night shift and seemingly face the greatest burdens of fatigue. In the trucking industry in particular, the American Trucking Associations (in partnership with the Federal Highway Administration and U.S. Department of Transportation) has published its own extensive guide for understanding fatigue in conjunction with training workshops on the subject.

To put the problem into perspective, a 1990 study by the National Transportation Safety Board found that 31 percent of crashes involving large trucks which were fatal to the truck driver involved fatigued truck drivers.

For Scarff, who regularly drives during the night (much of the driving at Pitt Ohio is done at night), it's an ongoing concern.

"There's no truck driver who can say they're not afraid of fatigue," he says. "It's been scary to me since the first time I stepped into a truck."

Uriah is quick to note that Pitt Ohio has always maintained a strict policy that requires drivers to rest at least eight hours between overnight runs and to call off work if overly fatigued or ill. He also says each run is timed to allow for breaks, tire checks and other things that indicate the company doesn't sacrifice safety for speed of service.

But as Damian Bierman, a research scientist at Carnegie Mellon Research Institute, says, "Even if someone gets adequate rest during the day, the opportunity to slip into a circadian trough at night is serious."

Until now, the trucking industry has preached awareness and education to drivers, teaching them about everything from effective on-road stimulants and how to detect drowsiness, to the advantages of strategic napping and how to get the best sleep at home. But when fatigue can't be avoided, what is a commercial driver to do? Especially when, as Bierman says, "the only thing that can effectively combat drowsiness is sleep itself?"

That's where the major scientific study comes in.

Several years ago, the National Highway Transportation Safety Administration contracted with Carnegie Mellon and the University of Pennsylvania to develop a noninvasive-but reliable-indicator of fatigue and drowsiness in drivers. Pitt Ohio joined the study two years ago, when it donated the use of seven of its drivers who volunteered.

Carnegie Mellon, overseeing this part of the study, studied the drivers initially in truck simulators and then set up a video camera and other recording devices inside the drivers' truck cabs. The initial goal, according to Bierman, is to develop an effective tool that accurately tracks the percentage of eye closure and detects driver drowsiness.

Scarff says it took him roughly two days to get used to the video monitor and resort to his normal driving patterns. "We smoked cigarettes, drank coffee and did whatever else we normally do," he says. "It didn't really bother us."

That phase of the study, which recently ended, netted Bierman and the other scientists an automated video system which, he says, can detect fatigue and drowsiness via measurements including eye closure, pupil movement, facial expressions and body movement. The video is protected by law from being used for accident reports, lawsuits and driver performance by Pitt Ohio, so drivers don't have to worry about repercussions from their driving habits.

The next step, Bierman says, is to develop an alarm triggered when the in-cab system detects drowsiness. He says researchers are contemplating a system that would release a strong peppermint scent or one with an audible alarm. Pitt Ohio's Uriah would like to see a system that would force drivers to pull off the road for a break when the alarm goes off.

The important thing, Bierman says, is that the system will be designed to detect drowsiness and warn the driver-but not stimulate the driver into ignoring his or her fatigue.

If the study goes as planned, Bierman says, the trucking industry will have a new, reasonably priced, high-tech system to protect drivers-and others on the road-from fatigue that could lead to accidents.

Uriah hopes it is adopted as an industry standard, so that economics don't rule out its use.

"It's good research that everybody can use and understand," Uriah says of the fatigue study. "I can't say enough about how great this study has been."