Citation

Bullough JD, Skinner NP, O'Rourke CP. Transport 2010; 25(3): 229-236.

Copyright

(Copyright © 2010, Vilnius Gediminas Technical University and Lithuanian Academy of Sciences, Publisher Vilnius Gediminas Technical University (VGTU) Press)

DOI

10.3846/transport.2010.28

PMID

unavailable

Abstract

Unlighted highway signs, which use newly developed retroreflective materials, were installed along the major expressway in an urban area by the local department of transportation. Photometric measurements of the signs were used to assess their legibility applying the relative visual performance model, in comparison to lighted signs, conforming to recommended illumination practices. The calculated visibility of the measured unlighted signs was similar to that of the signs equipped with exterior sign illumination. The practical significance and limitations of the relative visual performance approach are discussed.

Keywords: highway signs, visibility, visual performance, retroreflective materials