Stephen J. Heishman, PhD, Research Psychologist at the National Institute on Drug Abuse (NIDA), presented the following at the 1995 National Conference on Marijuana Use:

“Driving and marijuana do not mix; that’s the bottom line.

The data from these laboratory studies show that marijuana impairs balance and coordination — functional components important to driving — in a dose-related way. These effects may be related to reported marijuana-induced impairment of automobile driving.”