Transportation and design impacts of new ADA guidelines for public rights-of-way

Michele Ohmes, ADA Specialist, Public Works Department, City of Kansas City, Missouri

Mary O'Connor, Deputy Public Works Manager, City of Tempe, Arizona

In June 2002, the U.S. Access Board, the federal agency which develops accessibility guidelines for new and altered facilities under the Americans with Disabilities Act (ADA), issued a Notice of Availability for draft guidelines on public rights-of-way that will supplement its ADA Accessibility Guidelines (ADAAG). These guidelines, which cover access to sidewalks, street crossings, and other related pedestrian and roadway facilities, are based on recommendations from an advisory committee organized by the Board, the Public Rights-of-Way Access Advisory Committee. The draft is posted on the Access Board website,

The Public Rights-of-Way Access Advisory Committee (PROWAAC) included representatives from disability organizations, public works departments, transportation and traffic engineering groups, design professionals, civil engineers, government agencies and standard-setting bodies. APWA had two official representatives to this body, as well as government representatives and others who were also APWA members. The intent of this broad-based representation was to provide balanced guidelines that reflect a consensus among user needs and knowledgeable input from designers and implementers, resulting in a usable, comprehensive set of design standards.

In January 2001, PROWAAC presented its recommendations to the Access Board in the form of a report, "Building a True Community." This report is available on the Access Board website (, and has also been presented in various formats at the last two APWA Congresses and through local APWA chapters. The report focuses its recommendations on new construction activities in the public right-of-way.

The PROWAAC report was the basis for the draft guidelines published in June 2002. However, various items were changed in the draft. The Access Board is seeking comment on the draft, as well as feedback regarding usability and cost, in order to develop a proposed rule, which will provide another opportunity for public comment, after which the Board will finalize the guidelines. The guidelines serve as the basis for enforceable standards under the ADA and the Architectural Barriers Act (ABA). Ultimately, they also will comprise a new chapter of the ADAAG. The Access Board has scheduled a public hearing in Portland, Oregon on October 8, 2002. Written comments may also be sent to the Access Board.

A subgroup of PROWAAC continues to work with the Access Board on additional guidance materials focusing on alterations in the public right-of-way. This group has met in various locations around the country to gather information for real-world case studies to be included in the guidance materials.

APWA's Engineering and Technology Committee has been reviewing the initial draft guidelines in the PROWAAC report and has received a variety of comments from members. This article summarizes just some of the key information included in the new draft guidelines, and describes comments received from APWA members to date on the PROWAAC report.

Information contained in the new guidelines
The PROWAAC looked at the changes in the environment for pedestrians, especially those with disabilities, in the 10 years since the ADA was enacted. Currently, larger wheelchairs and scooters are in use, and new technologies are emerging. Ten years of experience in the design and maintenance of pedestrian facilities has identified a variety of issues that affect all pedestrians. Recent development of revised MUTCD guidelines and a new AASHTO pedestrian guideline document were coordinated with the work of the PROWAAC so that designers would have a consistent framework within which to work. When developing the draft June 2002 guidelines, which are based on the PROWAAC report, the Board considered the need for criteria for public rights-of-way which are definitive and enforceable so that local jurisdictions and others are clear on their obligations when constructing or altering streets or sidewalks.

Designers should be considering the following changes based on the new guidelines:

Sidewalk widths: provide a 48-inch minimum. Formerly, a 36-inch minimum clear sidewalk width was defined for accessibility. Current thinking on pedestrian design, as well as the presence of more pedestrians and the proliferation of larger wheelchairs and scooters, identifies the need for a wider sidewalk when new sidewalks are installed. The new minimum 48-inch sidewalk should be as free from obstructions as possible. The PROWAAC report had suggested a narrower route within the sidewalk that was smooth and free of surface features, such as textured paving or other rough or jointed surfaces ("reduced vibration zone"). The Board did not include this requirement because measurable technical specifications have not yet been identified.

Curb ramps: provide 48-inch width with flush edges, one curb ramp for each crosswalk alignment or a large combination ramp, detectable warning devices and a 48-inch by 48-inch level landing. For many years there has been a lack of consistency in implementation of curb ramp designs. The PROWAAC attempted, through review of field conditions, case studies and discussion with both designers and users, to define curb ramp solutions that are practical yet meet user needs. Formerly the minimum width for curb ramps was 36 inches, consistent with the minimum path of travel on sidewalks. Now, with the recommendation for a wider path of travel, the curb ramp width guideline has also increased to 48 inches. Also consistent with sidewalk guidelines, this area should be free of obstructions such as grates and poles. In order to assure that users can be directed to the crosswalk appropriately, the guidelines prioritize directional curb ramps (one for each crosswalk alignment) or one large combination ramp. Detectable warning surfaces must be included in the curb ramp installation (see below).

Detectable warning surfaces: truncated domes, required as of July 2001. Detectable warning surfaces are a requirement in the current ADAAG for the purpose of detecting the boundary between the sidewalk and the street. This requirement was suspended for a time to conduct further research. The research, part of PROWAAC's charge, resulted in recommendations based on input from blind and low vision user groups, wheelchair users, and designers and manufacturers.

PROWAAC recommended contrasting truncated dome surfaces as the most detectable surface underfoot, with visual contrast for low vision pedestrians. A recent FHWA memo (May 6, 2002) advises transportation agencies that the temporary suspension of detectable warnings in ADAAG expired in July 2001, and detectable warnings comprising truncated domes are now required when constructing and altering curb ramps. Grooves, exposed aggregate, and other designs are too similar to pavement textures, cracks and joints and are not considered equivalent in detectability. The Access Board is seeking comment on whether to require detectable warnings at all curb ramps and blended transitions, or only those least distinguishable by persons with vision impairments.

Crosswalks: Five percent maximum running grade, two percent maximum cross slope, 48-inch by 48-inch level street landing in front of curb ramps, extended crossing time. Current thinking on pedestrian design for all users encourages longer crossing times and flattened intersections to make crossing easier. A reduced vibration zone in the crosswalk, recommended by the PROWAAC, as well as a 3.5 feet per second crossing time, was not included in the June guidelines. The pedestrian crossing time recommended in the new guidelines is 3 feet per second.

Accessible Pedestrian Signals (APS): required for new construction and alterations, where pedestrian signals are provided. This guideline reflects advancing technology and a need for consistency in intersection treatments across the country for users with vision impairments. The draft guidelines require that accessible pedestrian signals should be provided where pedestrian crossings are identified with pedestrian signals (PROWAAC recommended only those which are pedestrian-activated). This guideline applies in new construction, when existing intersections are newly signalized, or where existing signal systems are changed significantly.

Alternate Circulation Path: where pedestrian routes blocked by construction, maintenance or other temporary conditions, requires a minimum 36-inch clear parallel alternate circulation path, with edge protection and railing. Construction at public rights-of-way can be particularly hazardous to people with visual or mobility impairments if the site is not adequately protected with a barrier which provides sufficient cues to enable a blind pedestrian to anticipate a hazard, or an edge along which to travel around an obstruction. Barrier requirements in the guidelines are based on MUTCD standards.

Comments/questions from APWA members to date:

Detectable warnings. One member commented that the truncated dome pattern does not work well in northern climates because of a tendency to trap water and freeze, creating a hazard. The comment was also made that the recommended safety yellow color does not fit with surrounding environments.

Members making the recommendation for the truncated domes included representatives from Alaska, Massachusetts, New York and other states, who are experienced with snow and ice conditions. The safety yellow color was selected to fulfill a very specific need for persons with low vision, who need a high level of color contrast in order to be able to detect the warning surface. The safety yellow color is not included in the draft guidelines, awaiting further research. A recent FHWA memo advised agencies that the use of detectable warning surfaces is a requirement as of July 2001, as described above. There are various agencies already implementing detectable warnings which can be contacted, and a variety of useful information is available on the Access Board website about the requirement, manufacturers, and recommended design.

Level landings at driveways. One member commented that the level landing across driveway approaches would not permit their standard detail to be used because of the required 2% cross-slope, and options their agency examined to revise the detail created drainage issues or barriers to vehicular capacity.

This is a good example of the type of situation for which PROWAAC members are developing technical assistance materials. The technical assistance will include matrices, design solutions, and case studies.

Cost of the recommendations, especially regarding traffic signals and roundabouts, and need for accommodation. One member commented that it is impossible to accommodate everyone or to achieve consistency from one city to another, and that the additional costs resulting from changes to the guidelines may delay implementation of items such as traffic signals or roundabouts.

Designers are often challenged to provide difficult or expensive design solutions to accommodate traffic, aesthetic or drainage considerations. Accommodation of pedestrians should be no less important than these considerations. The cost of implementation of the guidelines is simply the cost of doing business, and when considering cost, agencies should be aware that most of the guidelines are simply a clarification or update of existing requirements. OMB and Congress will be consulting local and state governments regarding the incremental cost of regulation during the rulemaking process.

What you can do
The guidelines contained in the PROWAAC report and the June 2002 draft guidelines represent best practices for an improved pedestrian environment for all users of our streets and sidewalks, including persons with disabilities. The federal regulatory process will take some time before these guidelines become law; in the meantime, applying best practices is a good approach to assuring that dollars spent on street and sidewalk improvements are well used, meet the needs of the entire community, and are defensible. If you begin to implement some of the new recommendations now, you will be able to observe their constructibility, maintainability, and usefulness, especially in the unique conditions of your area. This will enable you to comment effectively during the rulemaking process, and to identify additional areas for which technical assistance is needed.

APWA's Engineering and Technology Committee, as well as the Access Board, are interested in hearing from you during this period of public comment on the guidelines. Comments for the APWA committee can be forwarded to Ann Daniels at To contact the Access Board, you may call their toll-free technical assistance line at 1-800-872-2253, access their website at, or e-mail them at Also, information on this topic will be available at the September 2002 APWA Congress in Kansas City. Be sure to stop by the Access Board's Showcase Booth, as well as the scheduled roundtable session.

To reach Michele Ohmes, call (816) 513-2533 or send e-mail to To reach Mary O'Connor, call (480) 350-8819 or send e-mail to Mary_O'