A reversal design was used to evaluate the effects of vocal and written prompts as well as reinforcement on safe behavior (dismounting and walking bicycles or motorcycles on a sidewalk) on a university campus. Results indicated that an intervention that consisted of vocal and written prompts and reinforcement delivered by security guards was effective at increasing safe behavior exhibited by bicycle and motorcycle riders. No differences were observed between vehicle type or gender with regard to engagement in safe behavior. (Contains 1 figure.)