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The prevalence of drugged driving has increased in the United States, and some prescription medications (e.g., zolpidem) cause impairment after the predicted duration of therapeutic action has elapsed. The aim of this study is to determine if bedtime administration of alprazolam similarly impacts driving performance the following day. Volunteers were 14 healthy adults (6 males) who completed a double-blind, double-dummy within-subjects design study examining the effects of alprazolam (0.5, 1, & 2mg), zolpidem (10mg), and placebo administered at bedtime on driving performance the following day. The positive control condition was alprazolam (1mg) administered on the test morning. Driving simulator measures, cognitive and psychomotor tasks, and questionnaires querying drug effects were collected the afternoon before drug administration and for 5.5 hours the next day and analyzed using symmetry and mixed-model approaches. The positive control was robustly impairing. Driving impairment equivalent to that seen with alcohol at the legal limit was observed up to 12.5hr after bedtime alprazolam 2mg and for 8.5hr after bedtime zolpidem 10mg. Volunteers were not fully aware of their own level of impairment. These results suggest that alprazolam used before bed may pose an as yet unrecognized public safety risk in the form of next-day drugged-driving.