During weekday daytime, 12.1% of drivers tested positive for an illegal drug; 10.3% tested positive for prescription and OTC medications. During weekend nighttime, 15.2% of drivers tested positive for an illegal drug; 7.3% tested positive for prescription and OTC medications.

During weekday daytime, 12.1% of drivers tested positive for an illegal drug; 10.3% tested positive for prescription and OTC medications. During weekend nighttime, 15.2% of drivers tested positive for an illegal drug; 7.3% tested positive for prescription and OTC medications.

NHTSA 2013-2014 Roadside Survey)