The average age of the driving population is increasing. It is therefore likely that the proportion of drivers whose visual and cognitive abilities have started to decline will also be increasing. This awareness has prompted research which seeks to evaluate the appropriateness of current traffic sign standards, especially for the older driver. The ability of older drivers to extract information from signs has been studied and measurements made of the legibility of signs manufactured with different retro-reflective materials. Some of the newer sign materials were included in these studies to determine the effect of their greater brightness on legibility distances. Volunteer subjects in the 50-75 age group were invited to participate in a series of four experiments: (1) A test to examine reading times for direction signs of various complexities (using the TRL vehicle simulator); (2) A test to investigate the ability of older drivers to recall information from arrays of warning signs (also using the TRL vehicle simulator); (3) A full-scale night-time legibility experiment using different signing materials and levels of ambient brightness (on the TRL research track); and (4) A full-scale day-time experiment assessing sign legibility (on the TRL research track). (A)
Abstract