ADA Inspections Nationwide, LLC
The name of this company is ADA Inspections Nationwide, LLC
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by Richard Acree of ADA Inspections Nationwide, LLC

Sidewalk Curb Ramps

A sidewalk curb ramp is a short ramp cutting through a sidewalk curb or built up to it.    If designed and constructed to be accessible, a curb ramp provides an accessible route that people with disabilities can use to safely transition from a vehicular way or parking space to a curbed sidewalk and vice versa.  The different parts of the most common type of curb ramp, a perpendicular curb ramp, are labeled in the illustration below. The ramp, or ramp run, is the sloped section that individuals who use wheelchairs travel up and down when transitioning between the street and the sidewalk. Transitions between the ramp and the sidewalk, gutter and street are located at the top and bottom of the ramp run. Flared sides, or flares, bring the curb itself to the level of the street. The gutter is the roadway surface immediately next to the curb ramp that runs along the curb.

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Diagram of a Curb Ramp

So are curb ramps a big deal?

Short answer: YES!  Failure to provide accessible routes on municipal walkways has resulted in significant lawsuits against several cities including Atlanta, Los Angeles and Portland.  It is often difficult or impossible for a person using a wheelchair, scooter, walker, or other mobility device to cross a street if the sidewalk on either side of the street ends without a curb ramp. It is also dangerous. If curb ramps are not provided, these individuals are forced to make a difficult choice. They can either stay at home and not go to their chosen destination, or they can risk their personal safety by using their wheelchairs, scooters, or walkers to travel alongside cars and other vehicles in the streets. This is a choice that people with disabilities should not be required to make.

In Atlanta in 2018, a class action lawsuit for discrimination on the basis of disability was brought pursuant to Title II of the Americans with Disabilities Act, 42 U.S.C. §12131 (“ADA”) and Section 504 of the Rehabilitation Act of 1973, 29 U.S.C. § 701 (“Rehabilitation Act”), based on the City of Atlanta, Georgia’s (the “City’s”) systemic failure to maintain sidewalks that are equally accessible to persons with mobility impairments.  In the case document the following points were made in the complaint.

1. Among the community of disabled people living and working in the metropolitan Atlanta area, it is well known that the public rights of way within the City are, on the whole, difficult and sometimes impossible to navigate for those who rely on wheelchairs or similar devices for mobility.

2. A disabled person traveling in any given neighborhood of Atlanta will encounter along his or her path broken and uneven sidewalks, sidewalks obstructed by trees or utility poles, sidewalks obstructed by ongoing construction, intersections with missing curb ramps, curb ramps that are broken or otherwise unusable, and other impediments.

3. Navigating sidewalks and intersections in this condition is a dangerous enterprise. Disabled people often find themselves having to go into the street and move alongside vehicle traffic, at risk to life and limb.

4. Navigating sidewalks and intersections in this condition can be physically painful, jarring the person’s body or causing them to fall to the ground as they roll along uneven, broken pavement, holes in the right of way, or curb ramps that are not flush to the ground.

5. Many disabled people simply avoid going out into the world, fearing that they will become stuck at an intersection lacking a curb ramp, or that they will be unable to travel along a broken sidewalk.

6. This is not merely the result of a few sidewalks having fallen into disrepair. This is the result of a systemic, knowing failure by the City to maintain its public rights of way, on the whole, in a manner to ensure that they are equally accessible to people with mobility impairments. As shown herein, the City has been aware for many years of defects in a substantial percentage of its public rights of way, and has failed to budget sufficient funds or to commit sufficient resources to address the problem and maintain rights of way in a safe, ADA compliant condition.

7. The named Plaintiffs are individuals with disabilities who rely on ADA-compliant sidewalks, curb ramps, pedestrian crossings, and other walkways (collectively “public rights of way”) to meaningfully access and participate in the many services, programs, and activities offered to the City’s residents and visitors. They seek relief on behalf of themselves and a class of similarly-situated persons who, because of the City’s failure to maintain ADA compliant public rights-of-way, are denied equal access to the City’s public services.

8. Plaintiffs seek an order from this Court requiring the City to comply with the ADA and Rehabilitation Act by making reasonable modifications to its public rights of way, and meaningful adjustments to its policies and practices, so that Plaintiffs and those similarly situated may participate in and have meaningful access to the City’s services, programs, and activities.

In 2009, the Department of Justice (DOJ) and the City entered into a settlement agreement (“the Settlement Agreement”) as a result of a DOJ compliance review under the Title II of the ADA. (See Exhibit C).  In the Settlement Agreement the City agreed to implement a written process for soliciting and receiving input from individuals with disabilities on sidewalk accessibility, including requests to add curb ramps at particular locations, in compliance with 28 C.F.R. § 35.107(b), which requires the City to establish a grievance procedure for resolving complaints of Title II violations.  The City also agreed to provide curb ramps or other sloped areas at all intersections of the streets, roads, and highways that had either been newly constructed or altered since January 26, 1992.

On November 17, 2016, Lawrence Jeter, Senior Manager for the City’s Department of Public Works, testified in a deposition that, despite the 2009 Settlement Agreement, the City had not established a grievance procedure designed to allow disabled individuals to report non-compliant rights of way.  However, the Georgia Tech School of Civil and Environmental Engineering developed a “Sidewalk Sentry” application to allow users to report to a central database sidewalks and curb ramps that are deteriorated or otherwise non-accessible. As of March 9, 2018, there had been 2,158 individual reports of defective rights of way. Therefore, it was stated in the complaint that the City did not comply with its obligations under the 2009 Settlement Agreement to bring into compliance a significant number of non-compliant sidewalks and curb ramps along roads that were modified or repaired since 1992.

The cost to complete the repairs in Atlanta has not been published when this report was written.  A statement released by the plaintiffs attorneys said the city of Los Angeles, in 2015, settled a similar lawsuit by agreeing to allocate $1.3 billion over 30 years to bring its sidewalks into compliance with the Americans with Disabilit[ies] Act. Earlier in 2018, the city of Portland settled another such suit by agreeing to allocate $113 million over 12 years to fix its sidewalks and curbs.  According to the Next City website and an article published in 2016 by Anna Clark, when it comes to universal design, the most effective urban planning tool appears to be the threat of legal action. That's the case in Cedar Rapids, IA, where just a few years after a recent devastating flood, the Department of Justice began questioning the city's overall ADA compliance. The initial call came in 2011, and it took the Assistant City Manager by surprise.  She said, "Oh my gosh, it's one more thing. We're kind of up to our necks here."  But by 2015, Cedar Rapids signed a $15 million settlement agreement to rebuild as a truly accessible community. The Cedar Rapids settlement is one of more than 215 DOJ agreements of its kind under Project Civic Access, including 15 settlements nationwide last year (2017). They are designed to eliminate the physical and communication barriers “that prevent people with disabilities from participating fully in community life,” according to the project website.

Project Civic Access is a wide-ranging effort to ensure that counties, cities, towns, and villages comply with the ADA by eliminating physical and communication barriers that prevent people with disabilities from participating fully in community life. The Department of Justice has conducted reviews in 50 states, as well as Puerto Rico and the District of Columbia, and posts the agreements to help additional communities come into compliance with the Act. 

What Does the ADA Require with Respect to Curb Ramps at Pedestrian Crossings?

Title II of the ADA requires state and local governments to make pedestrian crossings accessible to people with disabilities by providing curb ramps.  This requirement applies if your state or local government has responsibility or authority over highways, streets, roads, pedestrian crossings, or walkways. Some public entities have extensive responsibility for the highways, streets, roads, pedestrian crossings, and walkways in their area, but most public entities have at least limited responsibility for them.

To allow people with disabilities to cross streets safely, state and local governments must provide curb ramps at pedestrian crossings and at public transportation stops where walkways intersect a curb. To comply with ADA requirements, the curb ramps provided must meet specific standards for width, slope, cross slope, placement, and other features.  In constructing facilities such as walkways and pedestrian crossings, state and local governments can choose between two sets of standards, the ADA Standards for Accessible Design (ADA Standards) and the Uniform Federal Accessibility Standards (UFAS).  Both of these standards have been deemed to comply with the requirements of Title II.  However, state and local governments cannot pick and choose between particular portions of the ADA Standards and UFAS as they construct or alter the pedestrian crossings on a street and the curb ramps that provide access to the adjacent sidewalks. Only one of these two standards may be used for a particular facility. In the construction or alteration of roadways and walkways, this typically means that only one standard may be used for a particular construction or alteration project, and all features of that project typically must comply with the chosen standard. Departures from particular requirements of either standard by the use of other methods are permitted when it is clearly evident that equivalent access is provided.

Installation Guidelines for Curb Ramps

So how hard can it be, right?  Well, the 2010 Standards for Accessible Design gives specific dimensions for the installation of a curb ramp.  Standard 406.1 [Curb Ramps] General, states, curb ramps on accessible routes shall comply with [Standards] 406, 405.2 through 405.5, and 405.10.  

Standard 406.2 [Curb Ramp] Counter Slope, states, "Counter slopes of adjoining gutters and road surfaces immediately adjacent to the curb ramp shall not be steeper than 1:20. The adjacent surfaces at transitions at curb ramps to walks, gutters, and streets shall be at the same level." In other words, the adjacent gutter and/or road cannot slope too steeply into the curb ramp.  The following diagram shows this relationship.

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Counter Slope of Surfaces Adjacent to Curb Ramps 

Standard 406.3, Sides of Curb Ramps, states, “Where provided, curb ramp flares shall not be steeper than 1:10.”  The following diagram shows this dimension.

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Curb Ramp Flare Max Slope

Standard 406.4, Landings, states, “Landings shall be provided at the tops of curb ramps. The landing clear length shall be 36 inches (915 mm) minimum. The landing clear width shall be at least as wide as the curb ramp, excluding flared sides, leading to the landing.”  The following diagram shows this installation.

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Landing at the Top of a Curb Ramp

Standard 406.5 [Curb Ramp] Location, states, “Curb ramps and the flared sides of curb ramps shall be located so that they do not project into vehicular traffic lanes, parking spaces, or parking access aisles. Curb ramps at marked crossings shall be wholly contained within the markings, excluding any flared sides.”  The photo below is an example of a curb ramp projecting into an access aisle.  


Photo of a Curb Ramp Extending into the Accessible Parking Aisle

Standard 406.6, Diagonal Curb Ramps, states, “Diagonal or corner type curb ramps with returned curbs or other well-defined edges shall have the edges parallel to the direction of pedestrian flow. The bottom of diagonal curb ramps shall have a clear space 48 inches (1220 mm) minimum outside active traffic lanes of the roadway. Diagonal curb ramps provided at marked crossings shall provide the 48 inches (1220 mm) minimum clear space within the markings. Diagonal curb ramps with flared sides shall have a segment of curb 24 inches (610 mm) long minimum located on each side of the curb ramp and within the marked crossing.”  The diagram below is an example of a diagonal curb ramp installation.

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Diagonal or Corner Type Curb Ramp Installation

The items in Standard 405 provide guidance on run slope and ramp cross slope limits and the surface conditions.  Standard 405.2, [Ramp] Slope, states, “Ramp runs shall have a running slope not steeper than 1:12.”  In other words, the ramp should not be sloped more than 1 inch per foot of run length.  See the diagram below.  Standard 405.3, [Ramp] Cross Slope, states, “Cross slope of ramp runs shall not be steeper than 1:48.”  In other words not steeper than 1 inch in 48 inches.  Standard 405.4, Floor or Ground Surfaces, states, “Floor or ground surfaces of ramp runs shall comply with [Standard] 302. Changes in level other than the running slope and cross slope are not permitted on ramp runs.”  Standard 405.5, [Ramp] Clear Width, states, “The clear width of a ramp run and, where handrails are provided, the clear width between handrails shall be 36 inches (915 mm) minimum.”  Standard 405.10, Wet Conditions, states, “Landings subject to wet conditions shall be designed to prevent the accumulation of water.”  In other words, no standing or pooled water on the ramp landings.  

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Maximum Ramp Slope

Standard 302 was referenced above.  Standard 302.1, Floor and Ground Surfaces, General, states, “Floor and ground surfaces shall be stable, firm, and slip resistant and shall comply with 302.”  Standard 302.2, Carpet, states, “Carpet or carpet tile shall be securely attached and shall have a firm cushion, pad, or backing or no cushion or pad. Carpet or carpet tile shall have a level loop, textured loop, level cut pile, or level cut/uncut pile texture. Pile height shall be ½ inch (13 mm) maximum. Exposed edges of carpet shall be fastened to floor surfaces and shall have trim on the entire length of the exposed edge. Carpet edge trim shall comply with 303.”  Granted, you won't find much carpet at exterior concrete curb ramps, but the rule applies to exterior and interior installations.  Standard 302.3, Openings, states, “Openings in floor or ground surfaces shall not allow passage of a sphere more than ½ inch (13 mm) diameter except as allowed in 407.4.3, 409.4.3, 410.4, 810.5.3 and 810.10. Elongated openings shall be placed so that the long dimension is perpendicular to the dominant direction of travel.”

One design issue to watch out for in curb ramps is the height of the elevation change to transition from the street level to the walkway.  Most curbs are designed to be 6 inches high, but some are taller.  Standard 405.8, Handrails, states, “Ramp runs with a rise greater than 6 inches (150 mm) shall have handrails complying with 505.”  

Another surface issue that can be easily missed is in Standard 303.2 [Changes in Level]  Vertical, states, “Changes in level of ¼ inch (6.4 mm) high maximum shall be permitted to be vertical.”  In other words, if a crack in the curb surface results in an abrupt change of more than ¼ inch, the crack has to be repaired.

And catch-all rules in implementation regulations 28 CFR, Parts 35-133 and 36-211, Maintenance of Accessible Features, states, "A public entity or public accommodation shall maintain in operable working condition those features of facilities and equipment that are required to be readily accessible to and usable by persons with disabilities by the Act or this part."  In other words, the ramps need to be maintained in good working order.  Flaking or cracked concrete may render the installation unusable.  This is also why it is important to hire an ADA Accessibility Inspector with experience in overall building inspections.

And lastly, ADA Standards for public transportation facilities issued by the Department of Transportation (DOT) require detectable warnings on curb ramps. They must extend the full width of the curb ramp (exclusive of flared sides) and extend either the full depth of the curb ramp or 24 inches deep minimum measured from the back of the curb on the ramp surface (§406.8). This requirement is unique to DOT’s ADA Standards (2006), which apply to facilities used by state and local governments to provide public transportation.  Other types of facilities covered by the ADA are subject to standards issued by the Department of Justice (DOJ). Neither DOJ’s ADA Standards (2010) nor the ABA Standards, which apply to federally funded facilities, require detectable warnings on curb ramps. However, the Access Board is developing new guidelines that will address access to public rights-of-way, including detectable warnings on curb ramps.  Stay tuned.


In summary, there is a clear requirement for municipalities and businesses to provide and maintain ADA accessible walkways and ramps on the accessible routes.  Failure to comply with the ADA can result in significant financial penalty and repairs.  Municipalities and businesses would be wise to audit their installations and, where necessary, implement a plan to update their curb ramps and walkways before the US DOJ comes to visit.  The installation of curb ramps that connect vehicle paths with walkways is a critical component of an accessible route.  The design and installation requirements are quite extensive and somewhat complex.  As with many laws, their are exceptions to those shown above.

If you observe a building that is not ADA compliant and you would like to know how to proceed, please see the link at What To Do When A Building Is Not ADA Compliant or Accessible.