The number of drunken drivers on the roads has fallen sharply over the past 30 years as laws and enforcement have stiffened and societal views on alcohol have shifted, according to a government survey released Monday. But the survey reported that 16.3% of drivers on weekend nights had tested positive for drugs.
The roadside survey by the National Highway Traffic Safety Administration found that 2.2% of drivers had blood-alcohol levels of 0.08% (the legal limit nationwide) or higher in 2007. The results represented a steady decline since 1973, when 7.5% of the drivers surveyed were legally intoxicated.
Using new screening techniques to detect substances in addition to alcohol, the survey found that the most commonly detected drugs in drivers were marijuana (8.3%), cocaine (3.9%) and methamphetamine (1.3%). Researchers said the presence of these drugs can remain in a driver's system for weeks, making it difficult to know whether the drivers who tested positive were impaired on the road.
"This troubling data shows us, for the first time, the scope of drugged driving in America and reinforces the need to reduce drug abuse," said Gil Kerlikowske, the director of the Office of National Drug Control Policy.
Be careful in the weekend wee hoursThe survey examined weekend nighttime drivers, collecting breath samples to measure blood-alcohol concentration. For the first time, it also collected oral fluid and blood samples to determine drivers' use of potentially impairing drugs.
Government researchers last conducted such a study on alcohol use in 1996, when 4.3% of drivers surveyed were legally intoxicated. In 1986, 5.4% of the respondents were legally drunk.
The drop-off has coincided with more-stringent efforts by law enforcement and advocacy groups such as Mothers Against Drunk Driving to reduce drunken driving, as well as the use of breath-monitoring devices for offenders that can lock vehicle ignitions. All 50 states and the District of Columbia have adopted a blood-alcohol concentration of 0.08% as the legal limit for drivers.
The study found a higher risk of encountering drunken drivers in the early-morning weekend hours: 4.8% of drivers had illegal blood-alcohol levels from the hours of 1 to 3 a.m. on Saturdays. It also found that 1.2% of drivers were legally drunk from 10 p.m. to midnight on Fridays, while 0.2% were drunk during the day.
Male drivers were 42% more likely to have illegal blood-alcohol levels than female drivers.
Motorcycle riders were more than twice as likely as passenger vehicle drivers to be drunk (5.6% compared with 2.3%). Pickup drivers were the next most likely to have illegal blood-alcohol levels (3.3%).
The survey was conducted at 300 locations around the country as drivers were randomly "directed" into the survey site by police officers. There, alcohol and drug tests were administered by non-law-enforcement personnel, who offered those found impaired a number of options for sobering up -- but not arrest.