Sleepy drivers are causing more accidents than federal officials have estimated, a new study said on Thursday.
Drowsiness was a factor in nearly one-tenth of the crashes suffered by 3,593 drivers who agreed to have video cameras and other monitors placed in their personal vehicles, AAA said in a report conducted by its Foundation for Traffic Safety.
Specifically, the nonprofit said, “8.8% to 9.5% of all crashes and 10.6% to 10.8% of crashes severe enough to be reported to the police involved driver drowsiness.”
The National Highway Traffic Safety Administration has pegged drowsiness as a factor in 1.4 percent of all crashes reported to the police.
AAA suggested the federal agency’s data might have been an undercount because sleepiness is hard to identify after a crash: No breathalyzer can capture whether motorists dozed off before collisions, and the sleep-deprived might fear reporting they were not alert — or not even be aware they were drowsy.
To Lisa Endee, a clinical assistant professor who studies sleep at Stony Brook University’s Respiratory Care and Polysomnographic Technology programs, the report echoes her own research that found the risks of drowsiness have been underemphasized.
“We understand drunk driving is a danger, drugged driving is a danger, and distraction has been more and more perceived to be a danger; I think drowsy driving deserves the same attention,” she said.
Endee, who helped devise a teaching program outlining this driving hazard, now is surveying 14,000 Stony Brook students who commute about its effects.
Anyone who works off-hours shifts, from police officers to health care workers, is particularly at risk, AAA said, as are younger drivers whose sleep might be shortened by parties, sports or social media, and older people who might sleep less and are more prone to sleep apnea.
The AAA’s Northeast spokesman, Robert Sinclair Jr., said that the motorists studied lived in Bloomington, Indiana; central Pennsylvania; Tampa, Florida; Buffalo, New York; Durham, North Carolina, and Seattle.
Those drivers had 905 severe, moderate and minor crashes, AAA said. Two-thirds were not serious enough to trigger police reports, noted Brian Tefft, a senior research associate at the Washington, D.C.-based AAA Foundation for Traffic Safety.
“What’s remarkable about this study is none were fatal; I think that might be a testimonial to the crashworthiness of the modern vehicle,” Sinclair said.
Researchers deemed drivers drowsy if their eyes were more than 80 percent closed in 12 percent or more of the video frames in the last minutes before the collisions, AAA said.
Anyone whose eyes could not be seen for at least 75 percent of that time — due to glare, dark sunglasses or poor video quality — was excluded.
Not surprisingly, nighttime appeared to be linked to dozing drivers. Drowsiness was “evident in over three times the proportion of crashes in darkness as in daylight,” the study said.
Some previous studies have suggested that drowsiness was an under-reported cause of accidents; AAA said it aimed to quantify that problem with the video cameras.
To prevent drowsiness from causing car accidents, AAA has the following advice for drivers:
Detect the warning signs:
— Difficulty keeping one’s eyes open;
— Drifting into another lane;
— Not being able to recall the last miles driven.
Limit the risks by:
— Sleeping at least seven hours;
— Not driving during hours when one usually is asleep;
— Not driving after heavy meals;
— Avoiding sleep-inducing drugs;
— Taking a break every two hours or 100 miles;
— Napping for 20 to 30 minutes — but no more;
— Traveling with passengers.