Often, sign failure is simply due to loss of retroreflectivity after the background material begins to reach its life expectancy. This is the usual cause of failure of the large guide signs on expressways and freeways. Retroreflectivity failure usually occurs to a group of signs facing the same direction at about the same time, since they were usually installed at the same time.

If the signs are no longer reflective, they should be scheduled for immediate replacement. Overhead guide signs with non-reflective backgrounds should also be refurbished when legibility is impaired by fading or streaking of the background.

Reflective Sheeting Performance

Department Materials Specification , “Sign Face Materials,” defines

The performance requirements cover the following possible defects and their associated tolerances:

Sign inspectors should be aware of this specification and be familiar with the sheeting application requirements and warranties.

The retroreflective quality of the sheeting material deteriorates over time, eventually requiring replacement of the sign. Premature failures of the sheeting should be reported to the Traffic Materials Branch of the Construction Division.