Tactile paving (also called tenji blocks, truncated domes, detectable warnings, tactile tiles, tactile ground surface indicators, tactile walking surface indicators, or detectable warning surfaces) is a system of textured ground surface indicators found at roadsides (such as at curb cuts), by and on stairs, and on railway station platforms, to assist pedestrians who are visually impaired.
Tactile warnings provide a distinctive surface pattern of truncated domes, cones or bars, detectable by a long cane or underfoot, which are used to alert the vision-impaired of approaching streets and hazardous surface or grade changes. There is disagreement between the design and user community as to whether installing the aid inside buildings may cause a tripping hazard.
A system of tactile paving was first instituted in Japan at pedestrian crossings and other hazardous road situations; the United Kingdom, Australia and the United States picked up the standard in the early 1990s. Canada started incorporating them into transportation first in the 1990s, and then added them to other aspects of the built environment in the early 2000s.