 Detectable warnings for pedestrian curb cuts were suspended for study in 1994, and became officially required in 2001.The ADA Accessibility Guidelines (ADAAG) require these warnings on the surface of curb ramps, which remove a tactile cue otherwise provided by curb faces, and at other areas where pedestrian ways blend with vehicular ways.They are also required along the edges of boarding platforms in transit facilities and the perimeter of reflecting pools.