Abstract
Objective: Cannabis-impaired driving is a growing public health concern, yet little is known about factors associated with cannabis use while driving (CUWD). No prior work has examined whether the method of cannabis administration used prior to driving is associated with CUWD; the present study addressed this gap. Method: Data were drawn from the baseline assessment of a randomized controlled trial. Participants were 149 emerging adults (18–29 years) who had driven after cannabis use at least three times in the past 3 months. Participants reported whether they had engaged in CUWD during that period and the method of cannabis administration (smoking, vaping, edibles, or multiple methods) used prior to driving on two cannabis-impaired driving occasions (most recent and heaviest). Two logistic regression models tested associations between administration method and CUWD. Results: Nearly two-thirds (61.7%) of participants reported CUWD in the past 3 months. Vaping prior to driving was associated with increased odds of CUWD on both the most recent (OR = 4.33, p < .001) and heaviest (OR = 2.78, p = .025) impaired driving occasions. Multiple-method use prior to driving on the heaviest impaired driving occasion was also associated with markedly higher odds (OR = 7.06, p < .001). Edible use was uncommon and not significantly associated with CUWD. Conclusions: Method of cannabis administration prior to driving is an important and underexamined correlate of CUWD. Vaping and multiple-method use may serve as behavioral markers of elevated risk and represent promising targets for screening, prevention, and method-specific harm reduction messaging.