Detectable Warnings on Curb Ramps

January 31, 2013

The 2010 ADA Standards do not require detectable warnings on curb ramps. They are only required at transportation platform boarding edges.

810.5.2 Detectable Warnings. Platform boarding edges not protected by platform screens or guards shall have detectable warnings complying with 705 along the full length of the public use area of the platform.

Requirements for detectable warnings are included in the proposed Guidelines for Public Right-of-Way. Although this document has not yet been adopted, it provides very good guidance for public ROW projects.

Here in Texas, a curb ramp located within a site is no longer required to contrast with adjoining surfaces or include detectable warnings or grooves.

Detectable warnings are required where accessible routes enter hazardous vehicular areas. This cannot be found in the 2012 TAS but is instead hidden away in the Texas Architectural Barriers Administrative Rules. A hazardous vehicular area includes all street crossings but does not include most driveways or pedestrian crossings within a site. Crossings at signalized driveways require detectable warnings.

Keep in mind that detectable warnings are required where are route enters a street even if there is no curb ramp.

The area covered by the detectable warnings should be limited to the 24″ minimum at the curb line. There is no benefit to providing more detectable warnings.

Contrasting Curb Ramps and Detectable Warnings

May 13, 2009

To quote the TDLR Technical Memorandum 08-01, “With the intention of harmonizing both State and Federal requirements, the Department issues the following technical clarifications regarding surface texture requirements at curb ramps.”

TM 08-01 then goes on to confuse the issue further by treating differently curb ramps within the public ROW (right of way) and those that are not within the ROW.

From the Texas Accessibility Standards (italics denote a change from the ADAAG):

4.7.4 Surface. Surfaces of curb ramps shall comply with 4.5.

(1) Textures shall consist of exposed crushed stone aggregate, roughened concrete, rubber, raised abrasive strips, or grooves extending the full width and depth of the curb ramp. Surfaces that are raised, etched, or grooved in a way that would allow water to accumulate are prohibited.

(2) For purposes of warning, the full width and depth of curb ramps shall have a light reflective value and texture that significantly contrasts with that of adjoining pedestrian routes.

Contrasting curb ramp on private property.

Contrasting curb ramp on private property.

Per TM 08-01, section 4.7.4(1) & (2) do not apply to curb ramps within the public ROW.  Instead, these curb ramps shall have detectable warnings that comply with section 4.29.2:

4.29.2* Detectable Warnings on Walking Surfaces. Detectable warnings shall consist of raised truncated domes with a diameter of nominal 0.9 in (23 mm), a height of nominal 0.2 in (5 mm) and a center-to-center spacing of nominal 2.35 in (60 mm) and shall contrast visually with adjoining surfaces, either light-on-dark, or dark-on-light.

The material used to provide contrast shall be an integral part of the walking surface. Detectable warnings used on interior surfaces shall differ from adjoining walking surfaces in resiliency or sound-on-cane contact.

The ADAAG(1991) and the revised ADA/ABA Guidelines(2004), do not specify contrast for curb ramps.  The contrast is a requirement for the detectable warnings which are required to be provided on curb ramps.

There is no conflict for curb ramps within the ROW; the contrast is only required on the detectable warnings.  The remainder of the curb ramp may be plain concrete.

If a curb ramp is not located within the ROW, section 4.7.4(2) still applies; the full width and depth of the curb ramp shall contrast with adjoining pedestrian routes even if detectable warnings are not used.

Don’t try too hard to understand it.  This story is not over.

Detectable Warnings on Curb Ramps required by the revised ADA/ABA Guidelines

December 11, 2008

UPDATE: The 2010 Standards do not require detectable warnings on curb ramps.
218 and 810 Transportation Facilities

Detectable Warnings. Detectable warnings provide a distinctively textured surface of truncated domes. The 1991 Standards at sections 4.1.3(15), 4.7.7, 4.29.2, 4.29.5, 4.29.6, and 10.3.1(8) require detectable warnings at curb ramps, hazardous vehicular areas, reflecting pools, and transit platform edges. The 2010 Standards at sections 218, 810.5, 705.1, and 705.2 only require detectable warnings at transit platform edges. The technical specifications for the diameter and spacing of the truncated domes have also been changed. The 2010 Standards also delete the requirement for the material used to contrast in resiliency or sound-on-cane contact from adjoining walking surfaces at interior locations.

The 2010 Standards apply to detectable warnings on developed sites. They do not apply to the public right-of-way. Scoping for detectable warnings at all locations other than transit platform edges has been eliminated from the 2010 Standards. However, because detectable warnings have been shown to significantly benefit individuals with disabilities at transit platform edges, the 2010 Standards provide scoping and technical requirements for detectable warnings at transit platform edges.

You may have been having problems finding the requirement for detectable warnings on curb ramps in the revised ADA/ABA Guidelines (published July 23, 2004).   You won’t find it here.

But you can find it in the March 23, 2007 supplement at this link: Modification to 406 of Appendix D

406.8 Detectable Warnings. A curb ramp shall have a detectable warning complying with 705. The detectable warning shall extend the full width of the curb ramp (exclusive of flared sides) and shall extend either the full depth of the curb ramp or 24 inches (610 mm) deep minimum measured from the back of the curb on the ramp surface.