Newswise — Dispensaries in one of the first US states to legalize recreational cannabis sales continue to disregard a law aimed at reducing the risk of consuming alcohol and cannabis simultaneously. Polysubstance use can lead to greater impairment and riskier behaviors than using either substance alone. Driving can be impaired even at low doses of both substances; this appears to have increased following the legalization of cannabis in many states. Current DUI laws do not adequately address polysubstance-intoxicated driving. It may be more effective to proscribe cannabis sales to people who appear intoxicated by alcohol, much as drinking establishments cut off sales to customers who seem alcohol-impaired. For the study in Alcohol: Clinical & Experimental Research, investigators assessed compliance at cannabis dispensaries in Oregon, a state that has such a law.