A field investigation of the effect off driver's age on nighttime legibility of highway signs was performed. Subjects of two age groups (under 25 and over 61 years of age) participated. The results indicate that the legibility distances for the older subjects were 65-77% of those for the younger subjects with equal high-luminance visual acuity. This finding implies that older drivers ar likely to have less distance (and thus less time as well) in which to act on the information transmitted by highway signs. Consequently, it is argued that (1) legibility standards for highway signs should not be based exclusively on data obtained from young observers, and (2) standard (high- luminance) acuity tests have questionable relevance to nighttime visual performance. (Author/publisher).
Samenvatting