"Epidemiological studies have been inconclusive regarding whether cannabis use causes an increased risk of motor vehicle accidents; in contrast, unanimity exists that alcohol use increases crash risk.30 In tests using driving simulation, neurocognitive impairment varies in a dose-related fashion, and symptoms are more pronounced with highly automatic driving functions than with more complex tasks that require conscious control.31 Cannabis smokers tend to over-estimate their impairment and compensate effectively while driving by utilizing a variety of behavioral strategies."


"Cannabis and the Regulatory Void: Background Paper and Recommendations," California Medical Association (Sacramento, CA: 2011), p. 10.