Deterioration of retroreflective traffic signs

The results are presented from the recently completed study, 'Service Life of Retroreflective Signs,' completed by the Federal Highway Administration, which investigated the factors that cause the deterioration of retroflective sheeting and ultimately reduce the effective service life of signs. The study focused on the two most commonly used sheetings: Type II, engineering grade; and Type III-A, high-performance grade. The FHWA has developed a sign management system for managing sign replacement programs and for ultimately assisting in maintaining a minimum level of retroreflectivity. The ability to predict the serice life of a traffic sign is essential to implementing the sign management system. To accomplish this, study objectives were established, the first of which focused on the factors that cause sign sheeting deterioration. To evaluate the deterioration factors, a national data collection effort was undertaken. This paper provides an overview of the data collection effort, and selected results from the sample data set.