Installation and use of back-and-forth audible traffic signal for visually impaired pedestrians

We examine different features of audible traffic signals capable of providing pedestrians with audible directional pointers at pedestrian crossings on roads of 20 meters wide or more, the installation of such signals, and appropriate intersections for their installation. Through this research we found that back-and-forth audible traffic signals, which emit the same or different sounds alternately, are more effective in terms of providing directional cues than conventional audible traffic signals which emit the same sound on both sides of a pedestrian crossing simultaneously. Additionally, we found that back-and-forth traffic signals using different sounds are preferable to ones using the same sound because with the former pedestrians at the midpoint of a crosswalk are unable to distinguish the sound coming from the front and that coming from the rear.