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Planning and Design for Alterations

PROWAAC Special Report

Chapter 1 - Introduction

by Mary O'Connor, Transportation General Manager, City of Scottsdale, AZ; Barbara McMillen, Pedestrian Accessibility Specialist

The Public Right-of-Way

The public right-of-way is a complex space serving multiple users and functions. The sidewalk and street crossing network is the basic unit of pedestrian mobility and its surfaces support all of us—from children to elders—in both pleasant and inclement weather. Private, transit, and commercial vehicles vie with pedestrians for right-of-way width. All modes of travel, including motor vehicles, rail transit, and foot traffic share time and space at intersections. Power companies maintain above-ground and below-ground transmission lines; municipalities own and operate surface streets and sidewalks; and utility companies and public agencies oversee below-grade sewers, water mains, gas mains, and data and telecommunication networks. The public right-of-way in large cities may include both air rights and underground circulation routes used by pedestrians. Adjacent to the right-of-way, private property owners construct, maintain, and operate buildings, entries, driveways, sidewalk vaults, basements, and other improvements and expect usable connections to and from public sidewalks and streets.

Over the last decade, roadway design principles have been expanded to include pedestrian travel accommodations that are increasingly being sought in residential neighborhoods and commercial centers in suburban and urban development. Designs are now expected to reflect equity and context and to balance pedestrian and vehicular use. The design pedestrian is now understood to be not an individual but a range of users—children, elders, people pushing or pulling strollers and delivery carts, using a wheelchair or scooter, or traveling with a long/white cane or a service animal—for all of whom the roadway and pedestrian environment must function effectively. Many of right-of-way users are people whose independent mobility requires pedestrian travel; they are best served by a network of accessible facilities that can provide efficient and safe route choices for a wide range of trip types.

Photo of a sidewalk widened to go around a pole that partially obstructs passage.
Photograph of a sidewalk widened to go around an obstruction.

Our extensive system of existing roadways is constantly being improved. The vast majority of work in the public right-of-way environment is reconstruction, alteration work, not new construction. The bulk of public works funds are used to maintain and to make changes in those existing environments, rather than to create new facilities. Each altered element must be accessible to and usable by people who have disabilities, to the maximum extent feasible. Integrating accessible features in planned alterations projects requires an understanding of both regulatory and usability concepts. This technical assistance publication has been developed to provide guidance in the planning and design of pedestrian improvements constructed as part of an alteration project. Its text, illustrations, and case studies aim to expand the reader's body of knowledge in accessible right-of-way design.

Accessibility Regulations

The Americans with Disabilities Act (ADA) of 1990 is a civil rights statute that prohibits discrimination against people with disabilities. ADA implementing regulations for Title II prohibit discrimination in the provision of services, programs, and activities by state and local governments. Designing and constructing pedestrian facilities in the public right-of-way that are not usable by people with disabilities may constitute discrimination. Section 504 of the Rehabilitation Act of 1973 (504) includes similar prohibitions in the conduct of federally-funded programs.

Thus, the accessibility objective in a new project is to design and build facilities that are ‘readily accessible to and usable by' people with disabilities. Compliance is measured against the referenced standards. From the ADA Title II implementing regulation:

(c) Accessibility standards. Design, construction, or alteration of facilities in conformance with [UFAS] or [ADAAG] shall be deemed to comply with the requirements of this section with respect to those
facilities …

Group photo of the members and staff of the Public Rights-of-Way Access Advisory Committee (PROWAAC).
The PROWAAC Committee at its January 2001 presentation of its recommendations for new PROW guidelines, “Building a True Community.”

Furthermore, equivalent facilitation—achieving accessibility's objectives by other means than are described in the standard—is recognized:

… Departures from particular requirements of either standard by the use of other methods shall be permitted when it is clearly evident that equivalent access to the facility or part of the facility is thereby provided.

However, ADA standards for new construction and alterations promulgated (as guidelines) by the U.S. Access Board and adopted by the U.S. Department of Justice (DOJ) in 1991 were principally developed for buildings and site work and are not easily applicable to sidewalks, street crossings, and related pedestrian facilities in the public right-of-way. Similarly, Section 504 standards (UFAS or ADAAG for USDOT, depending on the agency) did not offer guidance appropriate for rights-of-way construction. The need to address rights-of-way accessibility in a more specific way is apparent from the difficulties practitioners and agencies have in applying ADAAG to this very different environment.

Progress Towards Accessibility Standards for New Construction and Alterations in the Public Right-of-Way

The Access Board is the Federal government's specialist in accessible design. Under the ADA, the Board is responsible for developing the minimum accessibility guidelines needed to measure compliance with ADA obligations when new construction and alterations projects are planned and engineered.

In 1999, the Access Board started the rulemaking process for accessible pedestrian facilities in public rights-of-way by convening a Federal advisory committee of key stakeholders to develop recommendations that could supplement or replace the current standard. The Public Rights-of-Way Access Advisory Committee (PROWAAC) completed its initial work in 2000 and published its recommendations for new guidelines in a report, Building a True Community, which was presented at the 2001 Transportation Research Board Annual Meeting.

Resource: PROWAAC Report at:

On June 17, 2002, the Access Board issued a Notice of Availability of Draft Public Rights-of-Way Accessibility Guidelines (PROWAG) based on the PROWAAC report. Comments from consumers and design professionals led to the issuance of a second draft on November 23, 2005. A Notice of Proposed Rulemaking (NPRM) will follow seeking public comment prior to publication of a final rule.

Resource: November 23, 2005 draft PROWAG at:

The DOJ and U.S. Department of Transportation (DOT) are authorized by law to adopt standards consistent with the Access Board's guidelines for use in enforcing the ADA. The DOT has a similar authority under its Rehabilitation Act/504 regulation. The DOJ reviews 504 regulations issued by Federal agencies. When standards consistent with the final PROWAG guidelines are adopted by the DOJ, they will become the new minimum design standards under the ADA for both new construction and alterations of pedestrian facilities in the public right-of-way. The DOT has already indicated its intent to adopt the PROWAG, when completed, into its 504 standard.

In the interim, jurisdictions must continue to design and construct new and altered pedestrian facilities that are accessible to and usable by people with disabilities. The 2005 draft PROWAG has been identified by DOT as the current best practice in accessible pedestrian design under the Federal Highway Administration's Federal-aid (504) regulation.

Resource: FHWA Memorandum of January 2006 at: .

A temporary movable ramp and landing constructed of wood that can be set in a curb lane to provide access at a pedestrian detour.  The landing is enclosed by railings at its street edges. A temporary movable landing and ramp constructed of plywood that can be set in a street curb lane to provide access at a pedestrian detour.  Edge protection is provided by a low curb.
San Francisco uses plywood curb ramps with edge protection for temporary sidewalk detours.  Here PROWAAC member Ken Stewart of CCLVI (with white cane) tests a model while Lukas Franck of The Seeing Eye looks on.

Following completion of Building a True Community, the Access Board asked PROWAAC to develop guidance and recommendations focused on achieving accessibility in alteration projects within the public right-of-way. This advisory, Special Report: Accessible Public Rights-of-Way—Planning and Designing for Alterations, compiles the recommendations of a subcommittee of PROWAAC that worked to develop and highlight model rights-of-way design alternatives, design processes for making alterations, design solutions to specific problems, and case studies demonstrating examples of accessible design practices from across the country.


The focus of this report is on improvement projects in the public right-of-way that are classified as alterations under the ADA.

Alterations are discretionary changes, which the agency chooses to fund, to existing facilities within an already-developed right-of-way where the work affects, or could affect, the usability of that facility. ADA Title II implementing regulations require that each part of a facility altered by, on behalf of, or for the use of a public entity after January 26, 1992, be designed and constructed so that the altered parts are readily accessible to and usable by individuals with disabilities to the maximum extent feasible. While the following quote is from the ADA Title III regulation, it is a useful explanation of alteration and existing facilities.

b) Alteration. For the purposes of this part, an alteration is a change to a […] facility that affects or could affect the usability of the building or facility or any part thereof.

(1) Alterations include, but are not limited to, remodeling, renovation, rehabilitation, reconstruction, historic restoration, changes or rearrangement in structural parts or elements, and changes or rearrangement in the plan configuration of walls and full-height partitions. Normal maintenance, reroofing, painting or wallpapering, asbestos removal, or changes to mechanical and electrical systems are not alterations unless they affect the usability of the building or facility.

(2) If existing elements, spaces, or common areas are altered, then each such altered element, space, or area shall comply with the applicable provisions of appendix A to this part.

(c) To the maximum extent feasible. The phrase “to the maximum extent feasible,'' as used in this section, applies to the occasional case where the nature of an existing facility makes it virtually impossible to comply fully with applicable accessibility standards through a planned alteration. In these circumstances, the alteration shall provide the maximum physical accessibility feasible. Any altered features of the facility that can be made accessible shall be made accessible. If providing accessibility in conformance with this section to individuals with certain disabilities (e.g., those who use wheelchairs) would not be feasible, the facility shall be made accessible to persons with other types of disabilities (e.g., those who use crutches, those who have impaired vision or hearing, or those who have other impairments).

All state and local government entities are covered by this requirement. Regardless of whether state or local governments directly manage or delegate the development of facilities in the public right-of-way to the private sector, the same obligations apply.

Federal-aid facilities covered by 504 regulations follow a somewhat different approach, relating the scope of required accessibility improvements in an alteration to the scope of the overall project. When PROWAG is final, it is expected that FHWA Federal-aid regulations will be changed to reference the new document.

The Civil Rights Restoration Act of 1987 clarified that all programs and activities of Federal-aid recipients, subrecipients, and contractors are covered by 504 requirements. From a 1992 FHWA memo:

The efforts to prevent discrimination must address, but not be limited to, a program's impacts, access, benefits, participation, treatment, services, contracting opportunities, training opportunities, investigations of complaints, allocations of funds, prioritization of projects, and the functions of right-of-way, research, planning, and design.

Existing Facilities

Requirements for existing facilities and programs are stipulated in the DOJ ADA Title II regulation and the DOT/FHWA section 504 regulation. They apply a separate obligation for ‘program access' to existing facilities not otherwise being altered. From DOJ's ADA Title II technical assistance manual:

The Title II regulations impose a more generalized standard with respect to facilities covered by the ADA that were in existence in January 1992. Rather than applying the accessibility requirements to “[e]ach facility” that is covered (28 C.F.R. 35.151(a)), the regulations provide that a “public entity shall operate each service, program, or activity, so that the service, program, or activity, when viewed in its entirety, is readily accessible to and usable by individuals with disabilities.” 28 C.F.R. 35.150(a) (emphasis added). In addition, the regulations further provide that, even under this “entirety” approach, a public entity is not required “to take any action that it can demonstrate would result in * * * undue financial and administrative burdens.” 28 C.F.R. 35.150(a)(3).

The regulation governing existing facilities also provides that any “structural changes to facilities” necessary to comply with title II were to be made in accordance with a transition plan. 28 C.F.R. 35.150(d)(1). In particular, the regulation provides that such a “transition plan shall include a schedule for providing curb ramps” on “walkways” controlled by the public entity, “giving priority to walkways serving entities covered by the Act, including State and local government offices and facilities, transportation, places of public accommodation, and employers, followed by walkways serving other areas.” 28 C.F.R. 35.151(d)(2).

In assessing and addressing their responsibilities for existing facilities, many jurisdictions have relied heavily on two helpful tools—the self-evaluation and the transition plan. These tools were initially required under both 504 and ADA Title II regulations. Many jurisdictions have continued to use these tools to plan for addressing accessibility issues, assessing progress, and managing changing circumstances. In addition, DOT's 504 regulation requires that jurisdictions establish a system for periodically reviewing and updating the self-evaluation that forms the basis for the Federal-aid transition plan.

Paired curb ramps with detectable warnings at corner.
An urban intersection with paired perpendicular curb ramps, each with a 2-foot strip of detectable warnings at the toe. The flares have been shortened so that the ramps will both fit on the corner (flares are not a part of the pedestrian access route.)

A transition plan can provide decision-makers with an efficient tool for complying with section 504 and ADA requirements and holds information that often is not available in other planning documents. An updated transition plan will identify and locate elements and features that need to be added or altered, processes for determining accessibility priorities, and information that can be used in assessing the ‘undue burden' cost limitation in existing facilities. Cost is not a determinant in new construction and alterations.

While many methods may be utilized to achieve program access in existing facilities, ensuring usability in an already-developed pedestrian circulation system (a program) is likely to require remedial construction. In some cases, a new construction or alterations project will give rise to a program access obligation, as, for example, when a bus stop sign is placed in a hitherto-undeveloped environment. The presence of an existing bus stop that is not yet served by the pedestrian facilities needed to make it accessible—a pad for the deployment of a bus lift, a sidewalk for access to the stop—is a clear indicator of program access improvements that may need to be constructed for full use of the transportation system. It makes good economic and civil rights sense to look broadly at both responsibilities when new work is being planned and engineered.

Resources: DOJ's ADA title II regulation at:;
and a technical assistance manual at:;
DOJ's ‘Best Practices Toolkit for State and Local Governments' at:;
FHWA 504 regulation at:;
DOT planning documents at:;
DOT technical assistance at:;
DOT memo on the Civil Rights Restoration Act at:

The following chapters provide an overview of alterations projects from a regulatory and practical perspective. We hope it will help you implement accessible and usable pedestrian facilities under the most stringent of conditions—within the constraints of existing developed streetscapes. We include useful information on the planning and pre-design process for public right-of-way alteration projects; engineering drawings illustrating typical barriers in a range of roadway conditions; case studies of real-world solutions to access constraints; plans that demonstrate how accessible features can be incorporated into sidewalks of varying widths; model curb ramp examples; and resources from local, state, and Federal agencies.

This guidance has been drawn from expert practitioners across the U.S. and is focused entirely on improvement projects in the public right-of-way that can be considered alterations under the ADA. The design process for making accessibility improvements in alteration projects is not any different from the design process for traditional street modification projects. It involves the same use of standards, technical guidance, and product information that designers follow in every roadway design project. One key to success: recognition that ADA design standards are minima and maxima describing a range rather than design or engineering objectives. The running slope of a complying curb ramp may range between 0 and 1:12, but we suggest that designers set their calculations to fall within that range, not at its extreme, lest a construction or other anomaly affect compliance.

Case Study Examples

Throughout this Special Report are case study examples that illustrate alteration challenges and solutions applied to these challenges. Comments are provided to clarify the particular application and to provide the reader with background conditions to better understand the solution. Look for case study examples in a box similar to this one.

Case Study—Narrow Right-of-Way
  • A midblock crossing and perpendicular curb ramp are aligned with an existing building entrance walkway. The walkway serves as the level landing for the curb ramp and the work was coordinated with the abutting property owner.
  • Pedestrians can use the landing to bypass the descending ramp and its flares if they are continuing along the sidewalk.
  • The midblock crossing has a pedestrian signal with a call button and an APS with a locator tone.
  • Still needed: detectable warnings at the street edge.
Case Study: Front photo of a curb ramp showing how the required landing at the top of the ramp has been provided by the entrance walkway adjacent to it but beyond the right-of-way boundary.
Case Study: Side photo of a curb ramp showing how the required landing at the top of the ramp has been provided by the entrance walkway adjacent to it but beyond the right-of-way boundary.
Case Study—Narrow Right-of-Way
  • The roadway travel lane was narrowed to add width to the pedestrian sidewalk and to accommodate the relocated parking meters.
  • At the corner, a curb extension (bulb-out) into the parking lane provides the necessary space for a curb ramp and landing.
  • The curb radius was omitted at this non-turning corner.
  • Still needed: detectable warnings at the street edge.
Case Study: Front and side photos showing the addition of a curb extension (bulbout into the parking lane) at an existing corner to provide sidewalk space for a ramp at the crossing.
Case Study: Front and side photos showing the addition of a curb extension (bulbout into the parking lane) at an existing corner to provide sidewalk space for a ramp at the crossing.
Case Study—Downtown Redevelopment
  • The project required other improvements that offered opportunities for increased access: re-striping, new controllers and vehicle and pedestrian signals (existing equipment did not meet new MUTCD standards), and new curb ramps where bulb-outs were added.
  • New accessible parking spaces were located near intersections to take advantage of the curb ramp serving the crossing.
Case Study: After photo of changes to a small town Main Street. See case study discussion for detail.
Case Study: Before photo of changes to a small town Main Street. See case study discussion for detail.The before photo (left) is a downtown streetscape in Pottstown, PA that was the subject of an improvement project to invigorate downtown retail, add bike lanes, and increase parking. The after photos (left) show the changes: new angled parking, bike lanes and more visible markings. Case Study: After photo of changes to a small town Main Street. See case study discussion for detail.

Case Study: Photo showing temporary pedestrian route around construction. See case study discussion for detail.Case Study—Work Zone Accessibility

  • The photograph shows a same-side temporary pedestrian route that bypasses construction on the sidewalk.
  • Plywood surfacing is used where the route crosses grassy terrain; the joint is highlighted with contrasting paint. Still needed: a better bevel at the joint.
  • The edge of the plywood walkway provides an adequate wayfinding cue on the opposite side (it provides good sound-on-cane information.) Chain link fencing is poor as a channelization enclosure, since it is not easy to follow with a cane and usually requires ‘feet' that narrow the walkway.

Technical Assistance

Contact the Access Board for assistance on these guidelines