Inclusion Criteria:  Must have a driver's license; recent 2 years highway driving experience Cannabis use for at least the past 2 years and report of getting high when smoking cannabis to avoid recruiting novice/inexperienced users. Reports regularly drinking and smoking (does not need to be at the same time) Use cannabis at least 5 times within life up to daily use, with occasional day of abstinence with no symptoms of craving or withdrawal.  Exclusion Criteria:  Pregnancy, breastfeeding, and ineffective birth control methods. Current severe substance use disorder (except cannabis and tobacco substance use disorders) history of adverse effects with cannabis use serious medical, neuro-ophthalmological, or neurological illness (i.e. cancer, seizure disorders, encephalopathy) current diagnosis of any DSM-5 psychiatric disorder prior diagnosis of any DSM-5 psychiatric disorder report of any psychotic disorder in a first-degree relative history of head trauma with loss of consciousness > 30 minutes or concussion lasting 30 days. any medical/neurological condition that could compromise neurocognitive performance (i.e. epilepsy, multiple sclerosis, fetal alcohol syndrome) recovering alcoholics or anyone currently abstaining from alcohol.