“Traffic sign retroreflectivity” is a sign property which, during nighttime, causes light from a vehicle’s headlamps to be reflected back to the driver, giving the sign an illuminated appearance. The federal government has established guidance to ensure that agencies responsible for traffic signs will bring their signs up to an acceptable standard of retroreflectivity. The objective of this study is to provide examples of effective practices that illustrate how different types of agencies can meet the retroreflectivity requirements. Information was gathered through a literature review and telephone surveys. Case studies are included for four different agencies that participated in the survey.