More than likely, you have seen or utilized a detectable warning surface. Usually affixed at the end of sidewalk paths, along the edge of subway train station platforms, and on stair steps, detectable warning surfaces are common. These surfaces were created to assist those with disabilities when they are traveling in public. Being able to feel the end of a sidewalk, edge of a train platform, or the next stair step is vital for those that have disabilities like impaired vision. There are specific guidelines that must be followed in order for a detectable warning surface to be installed. These set of rules, in accordance with the Americans with Disabilities Act, were put in place to make sure that the detectable warning surfaces are all set to the same standards to help avoid mishaps and damages. The ADA requires the following when it comes to detectable warning surfaces:

The Size

The warning surfaces need to be large enough to be detectable while also not being too big that they completely overwhelm the area. These surfaces are covered in tactile domes and should be square or rectangle. The detectable surface should be 24 inches (0.61 m) and the length should be measured to these specifications going towards traffic and cover the entire surface. 

The Location

Location is important when it comes to a detectable warning surface. If the surface plates are not placed in the right location, they will be practically useless. According to the ADA, these warning surface plates have to be placed in vulnerable locations that can be difficult for the visually impaired to navigate. These locations include curb ramps, the edge of transportation platforms, as well as walkways. This is essential to protect the impaired for injury like slips and falls while they are navigating out in public. 

The Color

If you pay attention to detectable warning plates, you will notice that most of the time they are the same color. This is not by accident. According to the ADA, there aren’t specific requirements for these surfaces when it comes to color. In other words, the ADA doesn’t require the surfaces to all be yellow, green, or red. However, there are requirements as far as making sure they stand out. The detectable warning surfaces have to create a contrast to the color of the area that they are placed. Typically, the colors of choice are bright, easy to detect colors such as highlighter yellow, bright red, or a vibrant orange. If the surface is light, the detectable warning plates will be a darker color to help them stand out.