Retroreflectivity Maintenance
Measured Retroreflectivity Method
In this method, the retroreflectivity of a sign is measured and directly compared to the minimum level appropriate to that sign. If the sign retroreflectivity is lower than the minimum levels, the sign needs to be replaced. The following factors provide additional information about measuring sign retroreflectivity:
- ASTM E1709, Standard Test Method for Measurement of Retroreflective Signs Using a Portable Retroreflectometer, provides a standard method for measuring sign retroreflectivity using a handheld retroreflectometer.
- A sign needs to be replaced if the average retroreflectivity value is less than the appropriate minimum level.