Evaluation of Clearview Alphabet with Microprismatic Retroreflective Sheetings (0-4049-1)

This project was conducted to determine the legibility of the Clearview alphabet on freeway guide signs constructed with microprismatic retroreflective sheeting. The Clearview legibility results were compared to the legibility of freeway guide signs constructed with the Series E(Modified) alphabet. Also included in the analysis were legibility distances of freeway guide signs constructed with Type III sheeting.|A total of 60 subjects divided into three age groups participated in this nighttime study. The findings indicate that the Clearview alphabet provides statistically longer legibility distances than the Series E(Modified) alphabet. The findings also show that microprismatic sheeting provides statistically longer legibility distances than Type III sheeting. Sequentially, the differences between Type III guide signs with Series E(Modified) legends, microprismatic guide signs with Series E(Modified) legends, and microprismatic guide signs with Clearview legends were modest. However, the combined effect of switching from Type III guide signs with Series E(Modified) legends to microprismatic guide signs with Clearview legends were noteworthy. For overhead signs, the combined effect resulted in an overall mean legibility distance improvement of 70 ft, or 11.9 percent. For shoulder-mounted guide signs, the improvement was 74 ft, or 12.0 percent. Furthermore, the largest legibility distance improvements of the Clearview alphabet were associated with older drivers.