Countdown-Only Pedestrian Change Interval Displays

This study evaluated the effect of visual pedestrian signal displays on the ability of persons with reduced visual acuity to accurately and confidently identify the pedestrian interval. While watching video clips of actual intersections presented on a 42-in. monitor under simulated visual impairment, participants attempted to determine the pedestrian interval ("Walk," flashing "Don't Walk," or steady "Don't Walk") and provided confidence ratings for each judgment. Participants in Experiment 1 experienced simulated acuities of 20/70, 20/100, and 20/200; participants in Experiment 2 experienced approximate acuities of 20/20, 20/50, and 20/300. The study made a critical comparison of two methods of signaling the pedestrian change interval (i.e., flashing "Don't Walk"): (a) simultaneous presentation of a countdown and a flashing upraised hand symbol and (b) a countdown-only display without the flashing upraised hand. With the exception of performance in the 20/300 vision category, participants' accuracy on th...