Comparison between legibility of guide signs in diverse weather conditions

The legibility of expressway guide sign covered with retroreflective sheet generally tends to be deteriorated in adverse weather conditions. The purpose of this study is to compare and analyze the legibility of express guide signs in diverse weather conditions. In this study, legible distance of exit direction signs is collected from 4 subjects. In addition, guide sign system established at interchange of West Ansan in the 50th expressway route is modified from existing guide signs system. The size of panel, font, and arrow of modified guide sign system are different from existing guide signs system and these differences are made to improve both visibility and legibility. Accordingly, the effectiveness of modified guide signs system is also analyzed and the effect of diverse weather conditions on visible and legible distance of various expressway guide signs. In addition, Introduction of concentrating lighting signs is examined to ensure sufficient visible and legible distance regardless of weather for driver's safety.