Each year, about 1,500 people are killed, and 40,000 injured, in motor vehicle crashes involving a drowsy driver. There are various factors that can cause a driver to be drowsy, with sleep deprivation as the most common cause. In addition to the quantity and quality of sleep, drowsy driving is associated with other risky driving behaviors – such as drunk driving – that can increase the effects of fatigue, with various studies showing that people who tend to consume large amounts of alcohol over a short period of time are much more likely to fall asleep while driving.
According to the Centers for Disease Control and Prevention (CDC), drowsy driving is more common among binge drinkers than non-binge drinkers and abstainers. CDC analyzed a survey on the correlation between drowsy driving and other risky behaviors, conducted in 2012 among drivers in 10 states and Puerto Rico, and published a report explaining how a combination of driver fatigue and other risk behaviors can cause motor vehicle crashes with fatal consequences. The responses of 92,102 drivers were analyzed, with 4% of respondents saying that they have fallen asleep while driving at least once in the previous 30 days.
The survey found that young drivers are more susceptible to drowsy driving than the elderly, with 5.9% of those aged between 18 and 24 admitting to have fallen asleep behind the wheel in the previous 30 days, as opposed to only 1.8% of drivers aged 65 or older. In addition to questions related to the quantity and quality of sleep they are getting, respondents were asked how often they drink, whether they use seat belts while driving, and whether they currently smoke or have smoked in the past.
Results showed that binge drinkers – who are defined as those who have had five or more drinks at least once during the preceding month, for men, and four or more drinks, for women – are more prone to drowsy driving than abstainers, who are defined as those who had not had any alcohol during the previous 30 days. Also, the survey found that 6.6% of people who sometimes, seldom, or never wear seat belts while driving or riding in a car have fallen asleep on at least one occasion over the preceding month, compared to 3.9% of those who always or almost always use seat belts.
These findings can be very helpful in the efforts for reducing drowsy driving accidents, as they reveal that drivers who are susceptible to other risky behaviors are also more likely to fall asleep behind the wheel, indicating that enhanced enforcement on drunk driving laws, as well as seat belt use, could help prevent crashes involving drowsy drivers. As far as preventing drowsy driving is concerned, drivers are advised to get a good night’s sleep (between 7 and 9 hours) before driving long distances, avoid drinking alcohol, and consult their physicians if they have a sleep disorder, such as snoring frequently, or having difficulties sleeping at night.