ADA Warning Tiles Overview
There are approximately 23.7 million people in the U.S. who are blind or visually impaired. That’s 8% of the population. ADA warning tiles are part of a tactile detection warning system that helps to make the world accessible for people with mental health issues, hearing or visual impairment, blind, learning disabilities, chronic illnesses, and physical disabilities. For the purpose of this article, we’ll focus on ADA detection warning tiles for blind and visually impaired people.
What Are ADA Warning Tiles?
After the ADA was passed in 1991, the USDOT and USDOJ developed regulated guidelines requiring ADA detection warning systems (also known as tactile walking surface indicators – TWSI) be installed on certain surfaces, in certain areas, and under certain circumstances to allow Americans with disabilities to access the world independently, safely, and unaided.Often, “ADA warning tiles” will be used as a generic reference to a warning detection or TWSI product instead of its specific name.
ADA warning tiles usually have a truncated dome pattern with a regulated cone height and spacing. Placed at the beginning and ending of sidewalks and crosswalk intersections, directional bars may be placed at intervals along sidewalks and intersections to alert walkers to a change in direction or guide them on their path. These raised 4-strip wide bars, are also considered ADA detection warning tiles.

Where To Apply Warning Tiles
Some of the areas where TWSI would be applied include, but not limited to;- Sloped wheelchair curbs
- Sidewalk entrances and exits
- Pedestrian crossings
- Street intersections
- Top and bottom of curb ramps or any change in slope
- Sidewalks, paths and intersections indicating a change in direction
- Hazardous drop-offs like transit platforms edges or curb drop-offs
- Escalators
- Parking spots
- Public restrooms
- Government buildings, parks, and lands
How ADA Detectable Tiles Work
Federal guidelines require detectable warning systems to be:- A uniform size
- Made from highly slip-resistant surfaces
- Durable in high-traffic areas
- Low water absorption
- Easy to install and maintain
- Of recognizable non-fading colors that contrast with the surrounding environment
- Seen or felt through feet, canes, walkers, and wheelchairs
- Fully compliant with current ADA regulations
Terms to Know
- Americans With Disabilities Act (ADA) - Since 1990, this civil rights law recognizes the rights of disabled people in every area of public life. The ADA prohibits discrimination based on disability in jobs, transportation, and areas accessible to the general public.
The ADA requires employers, state and local agencies to provide reasonable accommodations to disabled employees and the public, and regulates accessibility to public buildings, parks, streets, playgrounds, and lands.
In order to create uniform accessibility, the federal government established ADA standards and ADA Accessibility Guidelines (ADAAG) requiring detectable warning systems nationally. Many countries have adopted similar standards.
- ADA Code Compliance – In 2012, through the Department of Justice, the 2010 revised ADA Standards for Accessible Design became the enforceable standards for new construction, alterations, program accessibility, and barrier removal (under Title II and Title III).
- ADA detectable warning systems - These unique ADA-regulated warning systems of pads, bars, and tiles are designed to help people with varying disabilities better navigate streets, buildings, sidewalks, playgrounds, and other public places independently and unaided. Detectable warning systems must be seen, heard, and felt. They increase the safety, accessibility, and enjoyment of public spaces for everyone.
- ADA detectable warning pads - Usually found at transit stations, curb drop-offs, and pedestrian crosswalks, warning pads are used anywhere a path has the potential to be unsafe. Truncated domes are the most common pattern and are easily detected by foot, cane, walker or wheelchair.
- Truncated dome is the most common pattern for ADA detection warning tiles. Featuring a unique pattern of raised “domes” that are easily heard, seen and felt by feet, canes, walkers, and wheelchairs, truncated domes provide visual and tactile alerts to the start and end of a path, sidewalk, or street or of a sudden and dangerous drop-off such as a transit platform. The most important factors are dome size, spacing, color, area size, location, and alignment. Domes must be large enough to be easily seen, but small enough to not be a tripping hazard. Using the dome pattern at the start and finish of a path, but combined with way-fairing bars at intervals along the path makes an accessible and safe walk.
- ADA detectable warning directional way-fairing bars and tiles are engineered with 4 strips to direct blind and visually impaired people in a specific direction along a path. They can be used in existing and new concrete substrates. They may be used in combination with truncated dome patterns, with the domes marking the beginning and ending of a path, while the way-fairing tiles direct pedestrians through the space.
- Public Right of Way (PROW) - A section of real estate where a city has acquired right-of-way interest. It may include the area on, below, or above, present and future streets, alleys, highways, and parkways. It does not include airwaves above the right-of-way with regard to wireless or non-wireless communications, utility or private easements in platted subdivisions or tracts.
- California Title 24 has additional and unique ADA requirements surrounding ramp slopes, tactile strips and other design elements that you should be familiar with if working in California, in order to be compliant and avoid expensive fines. Visit this site for the 2016 updated Building Codes on ADA requirements, a visual guide, and a handy ADA inspection checklist.