Although approximately 80-85% of the legally blind population has some residual vision, little research has examined the relative conspicuity of various types of visual pedestrian signals currently used by cities with this group of pedestrians. This research compared the relative conspicuity of an incandescent WALK sign, a white LED WALK sign, a blue LED WALK sign, and white and blue LED WALK signs that included an animated "eyes" display with legally blind participants who had some vision. All WALK signals were equated for brightness using a N.I.S.T.-certified illuminance meter. Participants had to discriminate whether the test stimulus was a blue/white WALK sign or a blue/white DON'T WALK sign. Test stimuli were presented in randomised blocks of trials, and recognition distances were determined by having participants approach the test stimuli until they could identify them. Results indicated that there were no significant differences between the incandescent and LED signals without the animated eyes or between the blue and white LED signals. However, Tukey's method showed a significant contrast between the signals with the animated eyes display and signals without this display (F=149.88, P value<0.0001). Participants could identify the WALK signal 62% further away when it also contained the animated "eyes" display. These results show that the addition of an animated "eyes" display to the WALK sign significantly improves recognition distance for a large segment of persons with visual impairment. (A)
Abstract