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A Control Sign Facility Design to Meet the New FHWA Minimum Sign Retroreflectivity Standards

Minimum sign retroreflectivity standards issued by the Federal Highway Administration (FHWA) on January 29, 2008, have focused the attention of administrators and sign managers on improving the nighttime performance of traffic signs. To predict when a sign will need replacement, an agency will need to know when the retroreflectivity of signs with similar characteristics deteriorate to the minimum level established by the FHWA. Currently in the literature, there is limited information about the long-term deterioration behavior of ASTM Type III and IX signs. One way of achieving a better understanding of long-term sign deterioration is to establish an experimental sign retroreflectivity measurement facility (ESRMF). An ESRMF is an arrangement of signs in a controlled area that have their retroreflectivity measured at regular intervals to determine how it deteriorates as a function of time. This article shows how such a facility should look and why. A template is presented that can be used by agencies nationwide for collecting critical sign data to inform policy decisions.