The failings of <i>per se</i> limits to detect cannabis-induced driving impairment: Results from a simulated driving study

Abstract

There appears to be a poor and inconsistent relationship between magnitude of impairment and THC concentrations in biological samples, meaning that <i>per se</i> limits cannot reliably discriminate between impaired from unimpaired drivers. There is a pressing need to develop improved methods of detecting cannabis intoxication and impairment.