Risk perceptions of driving under the influence of cannabis: Comparing medical and non-medical cannabis users

•Examined risk perceptions of driving under the influence of cannabis (DUIC) and alcohol (DUIA).•Compared perceptions of non-medical (ie. recreational) to medical or dual-purpose cannabis users.•Medical or dual-purpose users were more likely to agree that DUIC is safer than DUIA.•No difference found in perception that DUIC increases collision risk.•No difference found in perception that risk of police enforcement is higher for DUIA than DUIC.