The effect of color on license plate recall

Previous research has shown there are particular patterns of license plate designs that are easier to recall. Missouri license plate patterns (AB1-C2D) somewhat diverge from what research suggests works best for recall. The current study examined whether incorporating color into license plates would improve recall, and also whether awareness or explanation of license plate formats would affect recall accuracy. Across two experiments, participants viewed license plate stimuli with and without color and attempted to recall them. The hypothesis was that incorporating color would improve recall, but the hypothesis was not supported. Results also did not show that prior exposure or explanation of formats affected accuracy. Future research should explore additional ways to improve license plate designs that would be easy to implement. Such improvements to license plate design would be useful because efforts to improve the public's awareness of formats would be expensive and likely ineffective.