Countdown-Only Pedestrian Change Interval Displays

Abstract

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 the interval discrimination task was, overall, rather high. However, under simulated visual impairment of 20/70 or worse, participants' success in correctly determining the pedestrian interval was, on average, 21.5 percentage points lower for the countdown display presented without the flashing upraised hand than for the countdown display with the upraised hand. The participants' average reported confidence in their judgment was also lower for the countdown-only condition, and their interval judgment response times also showed a negative effect of the countdown-only display. Implications of the study findings with regard to visual impairment and signal displays for the pedestrian change interval are discussed.

Simulation of visual impairment in persons with normal vision for scientific research

“…Commercially available filters were used to simulate visual impairment in 23 5,32,36,46,48,[84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101] of the studies reviewed here. The major types of filters used included Bangerter occlusion filters (fresn el-prism.…”

“…com). Around two thirds 5,14,32,36,[87][88][89][90][91][92][93][94][95][96][97] of these investigations used Bangerter occlusion filters (Figure 5). These are a system of graded thin flexible patches with varying degrees of transparency that can adhere to the front of a spectacle lens, thereby blocking light transmission and reducing visual acuity in a graded fashion.…”

“…Commercially available filters were used to simulate visual impairment in 23 5,32,36,46,48,84–101 of the studies reviewed here. The major types of filters used included Bangerter occlusion filters (http://fresnel-prism.com), Vistech cataract filters (http://sbir.gov/node/347628), Bernell Cling patch filters (http://bernell.com) and the Peltor Ox 2000 polycarbonate filter (http://plexiglas-shop.com).…”

“…The major types of filters used included Bangerter occlusion filters (http://fresnel-prism.com), Vistech cataract filters (http://sbir.gov/node/347628), Bernell Cling patch filters (http://bernell.com) and the Peltor Ox 2000 polycarbonate filter (http://plexiglas-shop.com). Around two thirds 5,14,32,36,87–97 of these investigations used Bangerter occlusion filters (Figure 5). These are a system of graded thin flexible patches with varying degrees of transparency that can adhere to the front of a spectacle lens, thereby blocking light transmission and reducing visual acuity in a graded fashion.…”

Research on the operation of roundabouts based on the sustainable development principles

“…Motor vehicle collisions with pedestrians (Kopczynski et al 2011;Ptak et al 2012;Sokolovskij, Prentkovskis 2013) and bicycles (Loscorn et al 2013) at intersections has an impact on the increase in the number of road accidents. Pedestrians, crossing intersections in small interval, reduce their capacity (Scott et al 2013). Caliendo and Guida (2012) are modeling and assessing conflicts at deregulated intersections.…”