According to a study in the Journal of Concurrent Disorders, medical cannabis patients showed little change in simulated driving performance following cannabis inhalation.
The participants performed on a driving simulator before smoking marijuana and and 30 minutes afterwards. Three different simulated driving scenarios were used, NORML reported.
“The purpose of the present pilot study was to investigate the effects of therapeutic cannabis use on simulated driving. … It was found that therapeutic cannabis reduced overall mean speed with no effects on straightaway mean speed, straightaway lateral control, or brake latency,” the authors concluded.
The authors found that smoking marijuana didn’t appear to influence participants’ driving performance. The participants had low levels of THC (on average, 4ng/ml) in their blood before smoking cannabis for the simulator study.