Researchers at the Centers of Disease Control and Prevention in Atlanta said their analysis of responses from 147,076 drivers in 19 states and the District of Columbia found 4.2 percent reported having nodded off at least for a moment while driving at least once in the previous 30 days. Their findings were derived from answers to a set of questions about insufficient sleep administered through the Behavioral Risk Factor Surveillance System during 2009/2010.
Reports of falling asleep while driving were more common among adults who reported typically sleeping fewer than 6 hours per day, snoring or unintentionally falling asleep during the day compared with other adults who did not report these characteristics, the CDC said.
Sleepy drivers were blamed for 730 U.S. traffic deaths in 2009, and about 30,000 accidents involving drowsy drivers resulted in injuries, officials say.
Officials at the National Highway Traffic Safety Administration said although data collection methods made it challenging to estimate the number of crashes that involve drowsy drivers, modeling studies suggest 15 percent to 33 percent of fatal crashes may involve driver fatigue.