Detectable warning surfaces are used all around the world to enhance public safety and accessibility, targeted towards those with visual impairments. Truncated domes provide a non-visual warning of upcoming potential hazards, allowing the visually impaired to navigate public spaces safely, and unaided. To provide a standardized experience, detectable warning surfaces are subjected to stringent rules and regulations, which have been clearly outlined in the American’s with Disabilities Act (ADA).
Commonly made mistakes, however, can create potentially dangerous installations of detectable warning surfaces. Avoiding these mistakes places public safety and accessibility as a top priority!

Using Wayfinding Bars and Truncated Domes Interchangeably
Directional wayfinding bars and truncated domes are both important non-visual path marking cues, and each play a separate, distinct role.
The use of wayfinding bars signifies the start of a path to be followed, and are most commonly used to guide the visually impaired through large open spaces. Truncated domes, however, are used to alert the visually impaired to proceed with caution and identify the potential hazard. Truncated dome tiles are intended to be placed at the beginning and end of the pathway, signifying the end of the pathway and arrival of the potential danger.
Without truncated domes, the visually impaired are unable to identify the beginning and the end of the pathway and are not equipped with important non-visual clues of any potential dangers along the path.
Although directional wayfinding bars and truncated dome tiles are both ADA detectable warning surfaces, they are designed to be used together, and each play a specific and important role.
Installing Too Much or Not Enough
Detectable warning surfaces must provide sufficient notice of upcoming hazards, to allow the visually impaired to proceed with caution and act accordingly.
Too little of a detectable warning surface does not provide sufficient warning and can cause serious harm. For example, a narrow strip of truncated domes along the edge of a train platform may not be enough to warn pedestrians of the dangerous drop off and can lead to someone falling onto the tracks.
Installing too many ADA tiles on the other hand, can present significant safety concerns. Too large of detectable warning surface makes discerning the direction of travel difficult, leading to confusion and can possibly guide pedestrians into danger. Additionally, too many truncated dome tiles can make navigating the area difficult for walkers, wheelchairs, strollers, and other mobility aids.
The Americans with Disabilities Act (ADA) requires truncated dome tiles must extend at least 610mm in the direction of travel, and along the full width of the curb ramp, stair landing, blended transition or transit platform in order to provide sufficient warning.
Installed in The Wrong Areas
ADA detectable warning surfaces are required in several public areas, and are most commonly seen along transit platforms and pedestrian crosswalks.
Failing to install ADA tiles in the required locations, or installing them in the wrong locations, however, can be dangerous. Installing ADA tiles on stair landings signifies to the visually impaired the beginning and end of stairways, providing a non-visual path marking cue. Further, installing detectable warning plates on medians can be dangerous, as it could signify to persons with visual impairments, they’ve reached the other side of the pedestrian crosswalk.
Following local and federal building codes ensures detectable warning tiles are installed in the areas which will best serve the visually impaired.
Impeding Foot Traffic
Detectable warning surfaces are meant to enhance the safety and speed of pedestrian foot traffic, but when installed incorrectly or not following code, truncated domes can end up impeding the flow of foot traffic.
Truncated domes that protrude too high from the ground can cause a tripping hazard, and domes placed to closely together makes it difficult for wheelchairs, strollers, and other mobility aids to travel over the surface. Additionally, short truncated domes do not provide a significant tactile warning. The ADA places strict guidelines on the size and spacing of truncated domes to allow for the safe movement of people over the detectable warning surface.
Additionally, improper installation of detectable warning surfaces can lead to tripping hazards and even tile damage.
Following ADA detectable warning requirements not only help in the standardization of truncated dome tiles but helps avoid these common mistakes. Avoiding these common mistakes helps to enhance public accessibility and safety for persons of all abilities.
Access® Tile provides the ultimate solution in detectable warning surfaces. With millions of square feet of our industry-leading, cost-effective tactile warning tiles installed across North America, we are confident Access® Tile is the right solution for your next project. Our replaceable cast in place ADA tiles are the ideal choice for new construction and install easily into wet-set cement and make replacement a breeze. For retrofitting existing products, our surface applied truncated dome tiles are light-weight and easy to install, without the need to disturb the surrounding surface. To make the installation of ADA detectable warning surfaces at curb ramps and pedestrian crossings a breeze, both our replaceable cast in place and surface applied tiles are available in a variety of radial sizes.
Rely on our code compliance expertise and work with Access® Tile to create a more accessible environment!