For those who are not disabled, the relative ease of daily tasks is often taken for granted. The non-disabled have few problems getting to work, running errands, or crossing a busy street; the world has largely been designed for this majority. For a disabled person, however, the experience is very different. A visually impaired person, for example, may be unable to drive to work, have trouble using crosswalks, or be injured by a hazard he or she cannot see.

According to the World Health Organization, more than one billion individuals in the world are disabled in some way. Of those, approximately 285 million are visually impaired (having significantly low vision that cannot be helped with corrective lenses alone).¹ In the United States, the National Federation of the blind reports that more than seven million people have some form of visual impairment.²

Unfortunately, even with millions of disabled individuals worldwide, there are still many spaces that aren’t as accessible or safe for the disabled as they are for others. Because of this, the disabled tend to be at greater risk of an accident.

Common Accidents and Their Causes

The following are a few common types of accidents involving disabled persons, as well as their typical causes:

  • Falling
  • Common causes: Slippery surfaces that could not be avoided or foreseen due to their disability; tripping over hazards (e.g., uneven sidewalks); attempting to go upstairs when a ramp is unavailable.
  • Getting Hit by a Motor Vehicle
  • Common causes: Failure by drivers to acknowledge pedestrians in wheelchairs; inability to distinguish between the sidewalk and the road (if visually impaired).
  • Injury from Objects or Other People
  • Common causes: ADA non-compliance and unrecognized hazards (e.g., narrow store aisles), disregard for disabled individuals in a crowded space; lack of appropriate safety measures.

Using ADA Tiles to Prevent Accidents and Support Accessibility

One way to create safe, accessible spaces is to use ADA tiles to alert the visually impaired to areas bordering roadways, parking lots, and other areas of potential danger. ADA-detectable warning tiles feature a unique textured surface that can be felt through most types of footwear, providing a tactile alert to the person that he or she is approaching a curb or crosswalk. This type of warning is especially important now that curb design has become more sloped, making it more difficult to feel for the edges.

The use of ADA warning tiles for accident prevention and accessibility has numerous benefits for those installing them, as well. Using modular tiles to create tactile warning surfaces makes the application simple, flexible, and easy to replace. Focusing on accessibility and safety for the visually impaired also ensures that businesses aren’t alienating an entire group of potential customers.

The Unique Design of Detectable Warning Surface Tiles

Perhaps the most important aspect of tactile surface tiles is their carefully planned texture. While the bumps on the surface of the tiles may seem arbitrary, they’re manufactured to specifications provided in the Americans with Disabilities Act Accessibility Guidelines (ADAAG). The shape, known as the “truncated dome,” has been determined to be ideal for detectability and overall surface safety. To be compliant with the ADAAG, each dome must be within the defined height, diameter, and spacing ranges.

It’s not just about the truncated dome, however; every aspect of an ADA-detectable warning tile’s design is intended to support safety for everyone who might come in contact with it. The texture, for example, is important not just for being easily detected by visually impaired persons; it’s also perfect for providing grip in otherwise slippery conditions.

ADA tiles can also be manufactured in a variety of colors, the most popular being a bright, easily visible shade of yellow. These different color options make it possible for development planners to create high contrast between the tiles and their surrounding surfaces, making the tiles ideal as visual cues for the sighted.

The Americans With Disabilities Act

Your Obligations as a Business Owner or Public Servant

If you own a business or are responsible for planning a public space, you’ll need to make sure that your plans meet certain safety and accessibility standards. In addition to obeying all relevant building codes in your area, you have an obligation to meet ADA accessibility guidelines so that disabled individuals can easily access the space and be protected from accidents.

The ADAAG cover a variety of topics, including (but not limited to) the following:

  • Minimum accessibility requirements
  • Accessible room design
  • Bathroom stalls
  • Object heights (sinks, mirrors, hand dryers, soap dispensers, light switches, etc.)
  • Building entrance ramps
  • Detectable warnings (ADA flooring, ADA walkway requirements)
  • Detectable through footwear by the visually impaired
  • Sizing (minimum 6-8 inches from back of curb)
  • Truncated dome texture design
  • Signage
  • Curb Ramps
  • Usable by those with walkers, wheelchairs, scooters, etc.
  • Sloped transition from the street up to the walkway
  • Design of accessible routes
  • Doorways, elevators, hallways, etc.
  • Appropriate slope and width measurements
  • Alternatives to stairs
  • Sufficient turning space (for wheelchairs, scooters, etc.)

While following all of these different regulations might seem like unnecessary red tape, remember that they exist to protect and support the needs and safety of everyone, regardless of their abilities. It’s also not as difficult or time-consuming as you might think; ADA Solutions’ detectable warning surfaces, for example, are easy to order, install, and replace as needed.

Handicap Symbol on a Ramp

Before you solidify your plans or do any installations, make sure that you look into all of the relevant construction, safety, and accessibility laws in your state and community. Depending on where you live, you may have other legal requirements in addition to the federal ADA guidelines.

ADA Solutions Is an Industry Leader in Detectable Warnings

Whether you need ADA tiles for new construction, to correct compliance issues, or to replace old worn-out surfaces, you can trust the superior warning tile products at ADA Solutions. Our fully ADA-compliant tiles are made from heavy-duty materials like cast iron and fiberglass polymer composites, giving you years of reliable function without wear. Our tiles are also UV stable, which means that even years in direct sunlight won’t change their color or contrast.

ADA Solutions offers a range of detectable warning surface products for various applications:

    • Cast-in-place tiles (standard or replaceable)
    • Delivered ready for installation in freshly poured concrete.
    • Made from durable composite materials, ideal for long-term use.
    • Replaceable version has a surface piece that is anchored into panel body for easy replacement after years of wear.
    • Surface applied tiles
    • Ideal for retrofitting and quick installation (5-10 minutes, in some cases).
    • Thin, bevel-edged tiles provide a safe transition when installed on the surface of existing concrete.
    • Radius systems
    • Designed to support accessibility and ADAAG compliance along curved areas (radius conditions).
    • Easy, fast cutting with pre-scored radius measurements at 10, 15 and 20 feet.
    • No cutting needed for radiuses of 11-13 feet.
    • Cast iron “Irondome” tactile systems
    • Exterior grade tactile warning surface tiles cast from solid, extremely durable iron.
    • Natural finish of cast iron meets ADA color requirements.
    • Eligible for LEED® points (ideal for businesses seeking LEED® certification).
    • Replaceable graphic tile systems
    • Custom-designed tiles featuring full four-color graphics, messaging, and/or advertisements.
    • Artwork can be displayed across one or more tiles.
    • Replaceable for easy updating of graphics and messaging.
    • Other products
    • Photoluminescent “Glow-Dome” systems.
    • Wayfinding surfaces.

All of our tactile warning surface products are designed to meet ADAAG standards. With appropriate installation, our tiles provide full compliance and maximum accessibility.

To learn more about how you can prevent accidents involving the disabled and meet your obligations to safety and accessibility, explore our products online or call ADA Solutions at (800) 372-0519.



Detectable warning surfaces play an important role in our society’s efforts to improve safety and quality of life for men and women with disabilities. These truncated domes give sight-impaired people warning of hazards that may be present when they’re crossing streets or boarding trains or buses. A growing number of municipal governments and businesses are adopting them to meet Americans with Disability Act requirements and because it’s the right thing to do.

detectable warning surfaces truncated domes


Significant Sight-Impaired Population in the U.S.

There is a large population in the U.S. of the sight-impaired. The term “sight-impaired” is broad and covers a wide spectrum of people, including those who are legally blind and those who suffer from vision loss. According to the National Federation of the Blind, there are more than 7 million people in the U.S. who have significant vision loss. Worldwide, the World Health Organization estimates that 285 million people are visually impaired, and 39 percent of them are blind.

One of the major challenges of living with sight impairment is the impact it has on daily tasks that the sighted often take for granted. Tasks like walking to a nearby location or using public transportation become significantly more difficult—and even dangerous—when one cannot see obstacles and hazards in one’s path.

A study published by the National Center for Biotechnology Information found that blind people have significantly more difficulty in safely crossing streets when they had to rely on hearing alone to navigate the crossing. Truncated domes on ground surfaces provide a tactile warning to sight-impaired people that hazardous conditions or a change in conditions lies ahead, reducing the chance that these men and women will be injured.

detectable warning surface on sidewalk

What Are Detectable Warning Surfaces?

Detectable warning surfaces are ground surfaces that have a distinctive pattern of truncated domes that sight-impaired people can detect using their feet or a cane. Detectable warning surfaces notify sight-impaired people that street crossings or hazardous drop-offs are ahead.

For example, at a pedestrian street crossing where the pedestrian route transitions to the street route with a flush instead of a curbed connection, detectable warning surfaces would alert sight-impaired pedestrians to this change. At train stations or bus stops, detectable warning surfaces are used to indicate unprotected drop-offs along the edges of boarding platforms.

blind man with seeing eye dog

The ADA & Detectable Warning Surfaces

The Americans with Disabilities Act is the major piece of U.S. legislation dealing with access to facilities for the disabled. Originally passed in the 90s during the first Bush Administration, the ADA provides protections to people with disabilities, similar to those granted to various ethnic and religious groups under the 1964 Civil Rights Act.

The ADA is a complicated piece of legislation and covers many things, including accommodations at work for the disabled and how private and public facilities are designed. Making the legislation even more complicated is the fact that it is updated from time to time by the Department of Justice.

In general, when new ADA rules come down, facilities owners don’t have to tear up existing facilities to comply with the new regulations. Instead, when and if they upgrade their facilities, new construction must comply with ADA rules. This keeps business owners and municipalities from having to spend a lot of money to upgrade facilities every time new rules are announced.

In 2010, the U.S. Department of Justice released its 2010 ADA Standards for Accessible Design, which included new rules regarding facility design to improve accessibility for individuals with disabilities. The new guidelines were intended to improve accessibility to public and private spaces for people with disabilities, including the sight-impaired. The 2010 regulations revised regulations established in 2001.

yellow detectable warning surface next to sidewalk

The new guidelines created new rules regarding slopes for walking surfaces and slip-resistance for ground surfaces. In addition to these requirements, the 2010 ADA Standards for Accessible Design also created new rules for detectable warning surfaces.

The 2010 revision created some more lenient technical requirements for truncated dome sizes and placement on detectable warning surfaces. According to the new rules, domes should have a diameter of 0.9 to 1.4 inches. Their center-to-center spacing should be between 1.6 to 2.4 inches. Dome height should be 0.2 inches. The new guidelines give builders and facilities owners a little more leeway regarding spacing and diameter.

The major impact of the 2010 revisions to the ADA Standards for Accessible Design concerned changes to where detectable warning surfaces are required. According to the 2001 standards, truncated domes were required on curb ramps, in front of doors to hazardous areas, at dangerous vehicular areas, at transit platforms, and around the edges of reflecting pools.

blind person crossing street

The new standards are less demanding. Detectable warning surfaces are now only required on curb ramps in the public right-of-way and on the edges of transit platforms.

For companies not sure about whether they’ll need to upgrade facilities with detectable warning surfaces, a conversation with the Department of Justice or a supplier of detectable warning surfaces may clear up any ambiguity in the matter.

While many businesses don’t have to comply with ADA rules regarding detectable warning surfaces, compliance may be a good option, anyway. Having these surfaces in place could help businesses fight claims of negligence should disabled people be harmed on their properties. Installing infrastructure to make a property more accessible will also win a business the support of the disabled community in their area and will certainly be good public relations for that business.

Investing in making your facilities more accessible to people with disabilities can provide a nice return on your investment. The disabled community is growing in influence and wealth, and catering to this often-overlooked population can be lucrative. Nielsen estimates that one in three households in the U.S. has a member with a disability, representing more than $1 billion in spending power.

People can’t shop where they can’t go, so, by improving your facilities to make them more accessible for people with limited vision, you open your business to a group of customers with whom few other companies are doing business.

Recent Upgrades to Public Facilities

As municipalities upgrade and replace their sidewalks and other pedestrian infrastructure, many are adopting detectable warning surfaces to comply with ADA regulations and to receive grants linked to compliance.

For example, in Leetsdale, PA, the city government recently received funds from the Community Development Block Grant initiative, a federal program that aids low to medium-income areas. The funds are being used to renovate sidewalks on a major thoroughfare to be wider and to incorporate detectable warning surfaces. CDBG grants require sidewalk renovation projects to be ADA compliant.

Woodland Park, N.J. recently received $575,000 from the New Jersey Department of Transportation for upgrades to an often-traveled streetscape. The project will make a stretch of McBride Avenue more pedestrian- and bike-friendly and allow more convenient access to local merchants. A number of ADA renovations are being funded by the project, including the installation of barrier-free curb ramps, detectable warning surfaces, and more.

For municipalities and businesses considering making ADA-compliant changes to their facilities, partnering with a reputable maker of ADA compliant building materials can help ensure these projects are a success.

ADA Solutions is a leading manufacturer of detectable warning surfaces in North America. In business for 20 years, the company manufactures a variety of tactile dome and related products, including easy to install cast-in-place surfaces, durable surface applied panels for existing concrete or new construction, radius systems for curving surfaces, and more. If you’re looking to upgrade facilities and need an ADA-compliant ground surface, consult with ADA Solutions now for safe and reliable products.




Detectable warning surfaces provide a valuable service for those individuals with visual impairments. They essentially serve as a warning that requires their attention ahead, such as entering a busy intersection, a rail platform dropoff, and so on. In addition, these warning surfaces alert non-visually impaired, yet distracted individuals of the same warnings.

According to the Americans with Disabilities Act (ADA), detectable warning surfaces are defined as a distinct surface with a pattern of raised domes that can easily be detected by the use of a cane or feet and serve to alert people of their approach to hazardous locations.1

ada detectable warning near escalator

Reasons Why There Are ADA Requirements

The ADA was initialed passed in 1990. The Act affords similar protections for those individuals with disabilities as found under the Civil Rights Act. There are several Title areas of the Act that relate to:

  • Title I: Employment
  • Title II: Public Entitles and Public Transportation
  • Title III: Public Accommodations and Commercial Facilities
  • Title IV: Telecommunications
  • Title V: Miscellaneous Provisions

In regards to the requirements for detectable warning surfaces, Title II and Title III contain the information regarding the use of tactile warning surfaces. Title II focuses primarily on curbs, curb ramps, intersections, and other public areas where these surfaces are required. Title III focuses on altered/renovated or newly constructed places of public accommodations and commercial facilities.

Since the ADA was initially passed, there have been several updates to the regulatory compliances required for tactile warning surfaces. The most recent one was in 2010. It is the responsibility of facility managers, project managers, and others to ensure any existing, renovated or new construction meets the latest ADA requirements.

the americans with disabilities act

History of Detectable Warning Surfaces

Warning surfaces have gone through several generations since the ADA was first passed. Over the years, advancements have been made to ensure the truncated domes on the raised warning surfaces are durable and last a long time.

First Generation

The first generation solution was to simply stamp or score the concrete to create the elevated surfaces. It was a low-cost solution for contractors and builders since they only had to pour a new section of concrete in the required areas.

However, one major problem was that the concrete domes wore away quickly and could not easily be distinguished between cracks in the pavement and a warning surface. The use of this type of warning surface is not ADA-compliant under the current guidelines.

Second Generation

The second generation aimed to make improvements to warning surfaces by using bricks with raised domes. While the concept was much better than the first generation, there were still some issues with bricks.

To set bricks in place, the area around the location where the warning surface was to be installed had to be prepared using concrete. In addition, the ground underneath the bricks had to be compacted to ensure the bricks were level once installed. Gaps in between the bricks also had to be sealed to ensure they remained in place in the ground.

detectable warning brick surface

One reason bricks were not very successful is that the domes would wear off from being constantly walked on and from exposure to the elements. Furthermore, the bricks could become uneven, if not installed correctly, and create a slip, trip, and fall hazard. As such, truncated domed bricks are no longer allowed under the current ADA guidelines.

Third Generation

The third generation saw the introduction of surface-applied rubber and plastic domed solutions. These offered a better solution over the previous generations because they could be applied directly over an existing surface.

Contractors and construction workers no longer had to tear out sidewalks or other areas where truncated domes were required by the ADA. One concern when this solution first came out was the quality of the rubber and plastic materials used. They did not stand up to changes in temperatures, direct exposure to UV sunlight, and heavy foot traffic.

Yet one major change was the ability to create warning surfaces in a variety of colors, from yellow and red to blue and gray. Unfortunately, even with color options, the rubber or plastic would rip, tear, fade, and crack.

Whenever this occurred, the old one had to be completed removed and a new one installed. This led to ongoing maintenance in areas where these solutions were being used. In addition, they were not always installed in the exact location as required by the ADA.

Today, the ADA still does allow surface applied warning surfaces. However, they must be made from quality and durable materials. For instance, ADA Solutions surface-applied solutions are constructed of an exterior grade, high-quality fiberglass polymer composite material which is durable, weather resistant, and slip resistant.

Fourth Generation

The fourth generation saw the introduction of concrete inserts. This was a marked improvement over the original stamped or scored concrete. However, these inserts had similar problems to those truncated domes made from brick. The dome would wear off, the inserts could crack, and they were not designed for heavy foot traffic.

concrete detectable warning surface

These initial concrete inserts are no longer ADA compliant. Rather, there is a different type of concrete insert that addresses the previous concerns and problems, which the ADA does allow, although they can still be prone to weathering.

Fifth Generation

The fifth generation built upon the concept of using inserts and plastic-based materials. These new plastic inserts are commonly referred to as “Cast-in-Place” because they are set directly into the concrete while it is still wet.

The quality of the plastic materials was superior to concrete inserts. In addition, there is a variety of color options one can choose from when color is not mandated by state or local ordinances. The color of the insert resists fading from UV sunlight and is not prone to weathering like concrete.

Sixth Generation

The sixth generation saw new detectable warning surfaces being made from various metals, most often steel. The problem with steel warning surfaces is they had to be coated because you cannot color steel throughout. Even though steel is very durable, if the coating comes off, it leaves exposed steel that will rust and which could bleed into the pavement.

Metal inserts are still allowed under the ADA guidelines, so long as they meet the light-on-dark or dark-on-light requirement, as well as any state or local ordinances.

metal detectable warning surface

Seventh Generation

The latest generation of tactile systems includes several new products and solutions. Building upon the success of our high-quality surface applied products, we introduced our “Cast-in-Place Replaceable” panels in 2006. These panels have been a huge success and game changer and, so far, we have installed over 18 million square feet of our replaceable panel systems.

The replaceable feature makes it easy to swap out panels without having to tear up the concrete. Rather, the upper portion of the panel is removable and a new one can be installed in its place. This style is also popular when graphic tile systems are used as part of the warning surface.

Graphic tiles are a great way to incorporate images, logos, brands, or text messages into the ground. For instance, railway platforms could add text that says “Stand Back” or “Wait for Doors to Open before Boarding.”

Another type of product that we recently developed is our cast iron warning surface. The surfaces are made of durable cast iron and do not require coatings like steel and other metal warning surfaces. Since the dark cask iron color is consistent throughout, it maintains its appearance with its natural, unfinished state.

Radius systems are also another solution that we have brought to market in more recent years. This system transforms the traditional square or rectangular warning surfaces into arched and curved designs. This solution is perfect for corners at busy intersections or other areas where a curved or arch pattern is desired.

Last, this generation has seen the introduction of our Glow-Dome™ panels. These panels illuminate in lower light conditions to help provide non-visually impaired individuals with a distinct visual warning, as well as help guide them to emergency exits.

detectable warning surface on sidewalk

As you can see, detectable tactile warning surfaces have evolved quite a bit since 1990. Today you have numerous options to choose from that best suit your needs, from surface applied to cast-in-place and replaceable panels.

To learn more about our tactile dome systems and solutions or assistance in selecting the right warning surface products for your project, sidewalk, building, or another area, please feel free to contact ADA Solutions at (800) 372-0519 today!