First of Its Kind Study Finds Virtually No Driving Impairment Under the Influence of Marijuana
The first study to analyze the effects of cannabis on driving performance found that it caused almost no impairment. The impairment that it did cause was similar to that observed under the influence of a legal alcohol limit.
Researchers at the University of Iowa’s National Advanced Driving Simulator carried out the study, sponsored by National Highway Traffic Safety Administration, National Institute of Drug Abuse, and the Office of National Drug Control Policy.
“Once in the simulator—a 1996 Malibu sedan mounted in a 24-feet diameter dome—the drivers were assessed on weaving within the lane, how often the car left the lane, and the speed of the weaving. Drivers with only alcohol in their systems showed impairment in all three areas while those strictly under the influence of vaporized cannabis only demonstrated problems weaving within the lane. Drivers with blood concentrations of 13.1 ug/L THC, or delta-9-tetrahydrocannabinol, the active ingredient in marijuana, showed increased weaving that was similar to those with a .08 breath alcohol concentration, the legal limit in most states."
New Study: Minimal Driving Impairment From Marijuana - DUI BLOG January 7, 2016