In driving studies, Cannabis produces little or no car-handling impairment – consistently less than produced by moderate doses of alcohol and many legal medications. However, mixing
Cannabis and alcohol together amplifies potential risks. Surveys show that when THC is detected in the blood of fatally injured drivers, alcohol is often detected as well.
It is never a good idea to get behind the wheel when affected, even if just from Cannabis alone.
For some people, Cannabis may play a role in bad driving, but the overall rate of accidents does not appear to be significantly affected by the use of Cannabis. Also, people who frequently use Cannabis appear to develop a tolerance to its impairing effects.
Unfortunately, as a result of the criminalisation of Cannabis, harm prevention measures that exist for alcohol consumption – such as safe use guidelines, formal intoxication levels, designated driver education and easily accessible information about how alcohol impacts physical and mental functioning – are not widely available for Cannabis use.