TRB’s National Cooperative Highway Research Program (NCHRP) Web Only Document 72: National Calibration Facility for Retroreflective Traffic Control Materials is the full report of NCHRP Project 05-16, which developed dedicated reference instrumentation to provide national calibration standards for retroreflectivity, thereby improving the accuracy of measurements made by other instruments. A summary of the results of NCHRP Project 05-16 was published as NCHRP Research Results Digest 297: New Facility for Calibrating Retroreflectometer.