Determine which sign-retroreflectivity assessment method (visual nighttime inspection, measured retroreflectivity, control-sign monitoring, or another engineering-study method) a maintaining agency uses, and confirm signs meet MUTCD Table 2A-3 minimum levels.

Steps

1. Review FHWA's 'Methods for Maintaining Traffic Sign Retroreflectivity' (highways.dot.gov/safety/other/visibility/methods-maintaining-traffic-sign-retroreflectivity) and its Chapter 2 breakdown of the accepted assessment methods
2. Confirm the agency having jurisdiction has documented which method it uses: visual nighttime inspection by a trained inspector, retroreflectometer measurement, control-sign sampling, or another engineering-study-based method
3. Cross-check current minimum maintained retroreflectivity levels in MUTCD Table 2A-3 (e.g., White 120 cd/lx/m2, Green 25, Red 7, Orange/Yellow 75, and 250 for white legends on overhead signs) against the sign sheeting type in use
4. Confirm whether the assessment method requires nighttime-conditions inspection specifically (visual method) versus daytime-compatible instrument measurement (retroreflectometer method)
5. For control-sign programs, confirm which sample population (maintenance-yard sample versus in-field sample) is being monitored to trigger fleet-wide replacement