There has been an increase in prevalence of driving under the influence of cannabis (DUIC) and in fatal motor vehicle collisions in US states [1] and other countries following recreational cannabis legalization (e.g. Uruguay [2]; Canada [3]). Studies have found that acute cannabis intoxication is associated with a statistically significant increase in motor vehicle collision risk [4]. Cannabis impairs psychomotor skills critical to driving in both occasional and heavy users [5]. This is particularly concerning because of the increasing potency of Δ9-tetrahydrocannabinol (THC) concentration linked with more severe withdrawal and motor impairment [6].