The use of drugs by people driving cars is increasing. The use of alcohol is going down.
In 1973, 7.5 percent of drivers had blood alcohol level of .08 or higher. (A level of .07 is the legal limit in all 50 states.) In the new survey, the percent of people driving above the legal alcohol limit had fallen to 2.2 percent.
Breath, saliva, and blood samples came from randomly selected drivers in 300 locations around the United States.
Screening for drugs was a new part of the study. The survey screened for marijuana, cocaine and prescription drugs. The survey found that 16.3 percent of nighttime weekend drivers tested positive for drugs. Nearly 9 percent had used marijuana. Nearly 4 percent tested positive for cocaine. About the same number had used prescription drugs. The drug tests do not show if the driver was impaired.
The survey showed that more men used alcohol than women did. Drivers were most likely to be legally drunk between 1 a.m. and 3 a.m., and not daytime or evening hours. The vehicles most likely operated by drunk drivers were motorcycles and pick-up trucks.
The survey was voluntary and anonymous. Information came from all over the country. Drivers were selected at random and waved off the road to a survey location by police officers .The police did not do the interviews. Of the 11,000 drivers selected, about 90 percent gave breath samples and 70 percent gave saliva samples.
The police did not arrest drivers who were impaired. They did not get back on the road. Instead, they called for a ride or a passenger drove them home. The researchers drove some of the driver’s home themselves or got them a hotel room.