Complete stops at a high-traffic intersection on the campus of a public university were increased with a prompting and consequence intervention. Data were collected at two opposing stop signs (Stop A and Stop B); however, the intervention was implemented only at Stop A. During the intervention, a volunteer stood next to Stop A holding a poster that read, "Please Stop--I Care," with "Thank You For Stopping" on the reverse side. The poster was held by the volunteer so that drivers approaching Stop A could read the sign. Drivers approaching Stop B could see the volunteer but could not read the sign. When vehicles approaching Stop A made a complete stop, the volunteer flashed the "thank you" side of the poster to the driver. The strategy was evaluated using a multielement design. The intervention increased stops completed at Stop A from a baseline average of 13% to an intervention average of 52%. Stop B also showed improved stopping, from a baseline average of 6% to an intervention average of 28%. Data showed no relation between complete stops made and the drivers' use of turn signals and safety belts. (Contains 1 figure.)