Citation

Kenyon WD, Gurney GF, Bryden JE. Transp. Res. Rec. 1983; 933: 1-8.

Copyright

(Copyright © 1983, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The deterioration of reflective sign sheeting in New York State is examined, and the effectiveness of sign washing and clear-coating for restoring or preserving reflectivity of enclosed-lens engineer-grade sheeting is assessed. Generally, little benefit was achieved by washing all signs in the fall. However, changes in sign brightness, as measured by a retroreflectometer, indicate that significant brightness loss may occur during winter due to dirt accumulation, but that most signs recover after spring rains. The few that do not recover are readily identified by daytime visual inspection and would be the best candidates for washing. A large portion of these chronically dirty signs are located along high-volume highways, close to the pavement, and in industrial areas. The practice of clear-coating did not help maintain sheeting brightness; for the small sample included in this study, it had a detrimental effect. Candidates for replacement can be determined by nighttime visual inspection. Daytime cosmetic appearance alone should not determine need for replacement because signs with cracked or otherwise deteriorated sheeting may still provide adequate night visibility. Average sheeting life could not be determined in this study because no records were available for signs that had been replaced. An examination of the signs still in service determined that service lives of 15 yr in New York State are not unusual for enclosed-lens sheeting. Sign-replacement rates reported by maintenance engineers confirm that engineer-grade sheeting may retain adequate reflectivity for 15 yr or more.

Language: en

Keywords

TRAFFIC SIGNS, SIGNALS AND MARKINGS; HIGHWAY ENGINEERING