Impacts of Maintaining Traffic Signs Within Minimum Retroreflectivity Guidelines

The Federal Highway Administration has developed guidelines for minimum levels of retroreflectivity for four groups of signs: (a) black-on-yellow/orange warning signs, (b) black-on-white regulatory or guide signs, (c) white-on-red regulatory signs, and (d) white-on-green guide signs. The impact of implementing these guidelines was assessed by estimating the percentage of signs not meeting the proposed minimum levels and the cost of replacing such signs. Various state and local highway agencies assisted in the study by measuring the retroreflectivity of a sample of in-use signs, providing data on sign replacement costs, and commenting on the practicality of maintaining signs at minimum retroreflectivity levels. In general, the local agencies will have a higher percentage of signs needing replacement due to noncompliance with the minimum retroreflectivity guidelines than the state agencies, primarily due to a higher percentage of older and engineering-grade sheeting signs in service under their jurisdiction than the states. Overall, about 5.5 percent of the nation’s signs will not meet the minimum guidelines. About 8 percent of the local signs and about 4.5 percent of those under state jurisdictions will need replacement. Although warning signs will be the most critical signs for local agencies, the guide signs will be most critical for the states, each group requiring over 9.5 percent of the signs replaced. If all the signs not meeting the minimum guidelines are replaced, it would cost about $32 million to all the state agencies combined and about $144 million to the local agencies.