Drowsiness behind the wheel is a more significant safety problem on U.S. roads than previously thought, although cell phone use is the most common distraction for drivers, new research showed on Thursday.
Driver distraction was the cause of most auto crashes and near crashes in a year-long study of 241 drivers in the Washington, D.C., area conducted for federal safety regulators by the Virginia Tech Transportation Institute.
The most surprising finding, researchers said, was the accident rate among drowsy drivers. They were at least four times more likely to crash or narrowly escape an accident than rested motorists, the data showed.
Drowsiness contributed to 20 percent of all crashes and 16 percent of near crashes. Previous estimates blamed fatigue far less often.
“Drowsy driving may be significantly under reported in police crash investigations,” researchers said.
NHTSA partially funded the study that found driver inattention was a factor in 80 percent of all crashes and 65 percent of all near crashes.
In the study drivers, mostly male and aged 18 to 73, logged more than 2 million miles. They reported 82 crashes, 761 near crashes and nearly 8,300 critical incidents that required evasive action.
Cell phones and other hand-held communication devices were linked to the highest frequency of near crashes and incidents, according to researchers.
Dialing phone numbers was considered particularly dangerous. But the researchers found that cell phone use was so prevalent during more than 42,000 hours of driving that the overall risk of getting into an accident while using one was low.
Researchers used video cameras, automobile sensors, lane and speed tracking devices, and global positioning technology to track driver behavior and vehicle movements.
Drivers 18- to 20-years-old were four times more likely to be inattentive while driving that drivers 35 and older. These youngest drivers were also more apt to speed and drive aggressively.
Eating, applying makeup, reading, and reaching for objects, like the radio or CD player, were other distractions the researchers noted.