A fresh look at fatigue
Researcher Ron Knipling says fatigue and HOS are just a fraction of the real safety conserns on the highways

By David Tanner, associate editor

Safety groups use it, entire regulatory agendas are based on it, and yet it’s frequently misquoted and rarely used in the proper context.

Of course, we’re talking about the claims that driver fatigue plays a role in “30-40 percent” of fatal crashes involving trucks. The stat has been around for years, and the researcher who first used it says it’s routinely misused by people or groups pushing an agenda.

Meet Ronald Knipling, a former fed with FMCSA and NHTSA who is now an independent consultant. He’s authored dozens of studies involving safety and the human performance side of trucking, including fatigue.

Back in May, Knipling surprised a lot of folks during a two-day forum of the National Transportation Safety Board in Washington, DC, when after a long line of questioning, he finally explained the statistic and discussed how it is consistently misused.

“We had data suggesting a much smaller problem, but that was the number that was cited,” he said during the forum. The way in which safety groups and regulators use the number, “it’s not accurate,” he added.

The stat itself is solid, but not in the way people think, says Knipling who has done numerous interviews since the NTSB forum.

“It was one small study and I honestly don’t remember if they were fatal crashes or just serious crashes,” Knipling said in late June in an interview with Land Line Magazine and Land Line Now on Sirius XM.

He says a study for NTSB showed that 31 percent of crashes that were “fatal to the driver” have fatigue as a factor. But he adds that only one in 700 truck crashes is fatal to the driver. People often lump it all together, exaggerating the fatigue stat by as much as 30 times the overall crash rate.

“These are crashes where drivers died, so they’re important, but they’re not representative of all the crashes,” Knipling said. “So if you take that number and generalize it by mistake and just say ‘fatal’ or just say ‘crashes,’ you’re making an error in that.”

Unfortunately, safety groups and regulators keep generalizing that tired truckers are crashing and therefore all truckers need to be reined in.

“I don’t know whether people have done that intentionally, and I suspect they have because they want to emphasize the problem. Others do it by mistake. That’s one statistic that I don’t disagree with when it’s stated correctly, but it’s so easily misinterpreted,” Knipling said.

Knipling has been studying trucking safety, including fatigue, for more than 30 years. He has a degree in human-performance psychology. He says that not everyone is cut out to be a truck driver and that approximately 20 percent of drivers are half of the driver-related problems.

Fatigue-related risk has a different number. Knipling says approximately 13 percent of drivers are responsible for two-thirds of the fatigue risk on the highways.

He says the answer is not to restrict hours of service for all drivers. It should be identifying high risk drivers and treating the problem through retraining or getting the worst drivers out.

For the most part, Knipling is a big-picture kind of guy. He says safety goes well beyond hours of service.

“Based on everything we know, it would be unlikely that time on task – working and driving hours – would be a big factor in overall crash risk,” Knipling says.

Time of day, especially 4 a.m. to 6 a.m., is a factor. So is time a person is awake. Knipling says once a person reaches 16 hours awake, fatigue can set in regardless of task.  

“The important part is to see the big picture here. The big picture as far as fatigue goes is that time on task is possibly a factor, but there are other, much bigger factors,” Knipling said.

“You have to have hours of service, but we spend way too much time on them,” he adds. “It’s not the biggest thing affecting safety. The biggest thing affecting safety is other drivers, it’s traffic density, it’s truck drivers’ voluntary choices. Things like that. I even think medical issues are overemphasized.”

Knipling offered rebuttals to four studies that appeared in the federal hours-of-service docket earlier this year. He says he did it because the studies overgeneralized the relationship between HOS and safety.

“I was disappointed that they didn’t look deeper into it,” he said.

“Instead of trying to restrict all the drivers, with HOS or some other way, we should be focusing on identifying high-risk drivers. ... The vast majority of drivers are good drivers, and we should focus on helping them.”

That includes continuing education about fatigue and safety, he says, rather than a penalizing approach.

Knipling is a strong believer in graduated licensing.

“I think there should be a graduated system where more experienced, master drivers get some kind of a designation and recognition for that, so you have continuing professional development for drivers,” Knipling says.

A million miles might be a good benchmark for that, he believes. After that, drivers should be rewarded with more flexibility to drive and rest because they’ve obviously figured something out that works for them.

“If you’re only thinking fatigue,” he says, “it leads you down one path. But if you’re looking at the bigger picture, it leads you down a different path.” LL