The purpose of detectable warning panels is to alert the visually impaired that they are leaving a safe travel path. Typically, an edge, either a curb or step, can be detected by a cane and inform of a change in conditions. Where the curb is removed for a curb ramp or the path has a gradual slope to a pavement, an edge is not present, a detectable warning panel is installed.
The situation presented in the above photograph are two detectable warning panels on a staircase. These are unnecessary as the step edge is the appropriate warning. Detectable warnings at these positions may be a tripping hazard for the able. Later, the management company replaced the warnings with plain tiles.
Zimmer Consultants Photographs