Abstract
The effects of prompts and incentives on the frequency of designated driving at a bar frequented by undergraduates was tested. Using an A-B-A-B reversal design, the bar fluctuated between its regular program of offering designated drivers (DDs) free soft drinks and soda and an enhanced program in which posters and placards announced that the bar offered free nonalcoholic beers, wines, mixed drinks, and coffee to DDs. Observation showed that the prompts, incentives, and rewards caused an approximate doubling of the number of designated drivers.