Accessible Pedestrian Signals are a vital component of any pedestrian safety program for people who are blind or have low vision. Accessible pedestrian signals, commonly referred to as APS, provide both an audible and a vibrotactile method of informing pedestrians when the visual WALK signal is displayed. As a result of both a strong, multiyear community advocacy, spearheaded by the California Council of the Blind and the LightHouse for the Blind and Visually Impaired, a northern California agency, and the structured negotiations process, San Francisco now has approximately 690 APS devices installed at 70 intersections throughout the city. This article reviews the technical specifications that are being used in San Francisco and the advocacy effort behind the installations, and discusses the impact of APS on the community of people who are visually impaired.

Technical Specifications of San Francisco's APS

Details of the features, functions, and installation requirements for San Francisco's APS are included in the technical specifications that were negotiated as part of the APS settlement agreement. These specifications are available online at

The state-of-the art signaling devices that are being installed in San Francisco are manufactured by Polara Engineering ( and assist pedestrians who are blind or have low vision by emitting a rapid ticking sound in tandem with the familiar WALK symbol that is displayed for sighted pedestrians. The rapid tick was selected over the frequently heard "chirp" and "cuckoo" sounds on the basis of current research on pedestrian safety. Various devices were tested by the city and advocacy organizations before the final selection was made.

When the rapid tick is emitted, a large tactile arrow on the pushbutton also vibrates. This additional method of alerting pedestrians to the Walk phase is helpful both to pedestrians who are deaf-blind and to any blind pedestrian who may need or appreciate additional information regarding the Walk phase.

The APS in San Francisco also have "locator tones"—audible beeps to enable persons with visual impairments to know of their presence and to locate the devices. Many of the installations also provide other audible information, such as street names, when pedestrians press the pushbutton for one second or longer, which also increases the volume of the device. For example, when holding the pushbutton for one second or longer during the Walk phase, a pedestrian may hear "Walk Sign is on to cross Market Street." When the pushbutton is depressed when the Walk sign is not on, the pedestrian will hear "Wait to cross Market at Fifth Street."

The specifications also include information about the placement of poles, volume settings, and other installations and operational guidelines for successful APS placements. These specifications were designed to ensure the safest possible installations and a seamless integration with the city's general pedestrian signal program. For example, the specifications require that if a visual signal is a "fixed time signal" (a signal that does not require the pedestrian to push a button), then the audio and tactile aspects of the signal are also fixed time.

APS features, functions, and installation requirements are spelled out in great detail in the San Francisco APS agreement because, as with many accessible technology issues, "the devil is in the details." Because APS are also a safety issue, in addition to being a civil rights and access issue, the proper installation takes on added significance. For example, the technical specifications spell out the details on volume control by providing that both the locator tone and the walk signal "shall be audible, under varying conditions of ambient sound, 6 feet to 12 feet from the pushbutton, or to the building line of the nearest building, whichever is less" (Section 2 of the technical specifications). The agreement further provides that "volume shall be increased for one, or if available from the vendor, two Pedestrian Timing cycles following a button press of one second or more."

There are similar details about the placement of the poles upon which the APS are mounted. Absent specified defenses, APS are to be "installed such that the APS Control Surfaces and associated speakers are separated by a horizontal distance of at least 10 feet" (Section 2.3). Furthermore, "all APS Control Surfaces shall be placed so that the Control Surface is within five feet of the extended crosswalk lines, and not more than 10 feet from the edge of the curb unless the curb ramp is longer than 10 feet. The Control Surface of the Accessible Pedestrian Signals shall be oriented to be parallel to the crosswalk to be used. In addition, the poles on which Accessible Pedestrian Signals are placed in new or altered Intersections where new poles are installed, where feasible shall be located 10 inches or less to a level, firm, stable, slip-resistant, all-weather surface no less than 36 inches by 48 inches and on an accessible route to the curb ramp. (All dimensions are horizontally measured.)"

The foregoing specifications for the placement of poles and volume settings give an idea of the level of details contained in the technical specifications that were negotiated as part of the San Francisco APS agreement. In addition to the reasons just stated, these details are important because they allow for consistency for travelers who are visually impaired in San Francisco. In San Francisco, all APS units behave the same way, and there are not multiple types of units configured in various ways throughout the city. The APS details that are set forth in the technical specifications are critical to ensuring that APS provide effective information in as safe a manner as possible for pedestrians with visual impairments.

Why APS Matter

APS have a proved track record internationally of improving safety for pedestrians with visual impairments. Jessie Lorenz, the coauthor of this article and the director of public policy and information for the LightHouse for the Blind and Visually Impaired in San Francisco, provided the following firsthand account of their importance from the perspective of a pedestrian who is blind.

"I have been involved in the San Francisco disability rights community for 10 years. When I started, San Francisco had one accessible pedestrian signal, located at San Francisco State University. There are now over 60 intersections with APS units. The audiotactile information that APS provide about the Walk cycle is something I have spoken about a great deal in public meetings. I truly feel that APS are an important part of the civic infostructure. (I may be coining the word "infostructure" in this article, but I don't mean "infrastructure." There is a complex web of information provided by public entities in all public places. As a blind person, I need as much access to that information as I can get.)

"Although I had known of the political, safety, and civil rights importance of APS for many years, the meaning of APS in my own life crystallized for me only eight months ago when I got off the streetcar mistakenly at the wrong stop. I was going to a new place and miscounted the number of stops to my destination. So here I was in an unfamiliar place, completely blind and in the middle of a busy street trying to orient myself. The streetcar stops on an island in the middle of the street. I could hear the locator tone on the Polara Navigator beaconing sound. I found the unit, read the braille on the unit, and was immediately able to determine what streets I was at. I decided to walk the rest of my route to my destination. The APS units along my journey enabled me to double check the names of streets and cross with the Walk cycle on streets that were unfamiliar to me. I got a little more exercise that morning and wasn't even late for my appointment! It was the first time I have ever felt like I live in a fully accessible community."

Stories like these must be shared with traffic engineers across the country who may not yet be familiar with the importance of APS installations.

Structured Negotiations Process

The devices in San Francisco are the result of a successful multiyear advocacy campaign by the California Council of the Blind, the San Francisco LightHouse, and others. Before the campaign, only one intersection was equipped with Accessible Pedestrian Signals in the entire city. Using the structured negotiations process instead of litigation, the community of persons who are visually impaired and the city hammered out an agreement in 2007 that has resulted in the installations to date. In the settlement agreement, the city agreed to install APS at a minimum of 80 intersections and to spend a minimum of $1.6 million on APS over a 2½-year period. The agreement also provides that the city will seek additional funding for more installations.

Structured negotiations is a process that avoids litigation and allows potential adversaries to work collaboratively to resolve accessibility issues. The method has been used to improve the accessibility of web sites; to provide credit reports in braille, large-print, and audio formats, as well as in accessible formats online; to convince banks to install Talking ATMs and provide alternative formats; and to work with retailers in providing tactile keypads so that customers with visual impairments can independently enter PIN numbers and other personal information. The process was particularly helpful in pressing the San Francisco visually impaired community's need for APS. Advancing technology and new research on safety demand that the parties have an ongoing constructive relationship to resolve issues as they arise. Litigation often prevents such a relationship from developing.

The written settlement agreement guarantees the ongoing relationship by containing a provision that requires San Francisco representatives to meet twice a year with representatives of the visually impaired community to discuss implementation issues, as well as any new technological, legal, or safety developments in connection with APS. The city has also agreed to maintain the new devices and has adopted a policy for San Francisco residents to request accessible pedestrian signals. (The policy is available online at San Francisco has also adopted a detailed checklist to enable it to establish priorities among APS requests fairly on the basis of safety factors and other criteria. As with the APS, the "prioritization tool" was adapted from a detailed state-of-the-art research document provided by consultants who assisted in the negotiations. More information on such tools is available on the web site of Beezy Bentzen and Janet Barlow, two of the consultants who were involved in the San Francisco APS effort, at and

Further evidence of the positive relationship that was spawned as a result of the San Francisco APS advocacy effort can be found in the press release that was jointly issued when the program was announced. City officials praised the community advocates and the structured negotiations process, and San Francisco's city attorney stated: "This agreement reflects far more than our commitment to public safety—it represents San Francisco's commitment to engage the disability community in a manner that is cooperative rather than confrontational on matters involving accessibility and compliance with the Americans with Disabilities Act. ... [I am] thankful for the positive approach taken by advocates for the blind and visually impaired community."

Learn More

AccessWorld readers are encouraged to share the information in this article and the following resources with community members, local traffic engineers, and other state and local officials. Pedestrian safety is a critical issue for people who are blind or have low vision, and APS should be a significant part of all pedestrian safety programs.

The San Francisco APS settlement agreement and related documents are available on Lainey Feingold's web site, The direct link to the settlement agreement is The APS technical specifications can be found at Lainey, along with civil rights lawyer Linda Dardarian ( represented the visually impaired community in negotiations with San Francisco.

Jessie Lorenz, director of public policy and information, LightHouse for the Blind and Visually Impaired, is the principal advocate who is helping San Francisco implement the historic APS agreement. She can be reached at 415-694-7361 or

Eugene Lozano, Jr., first vice president of the California Council of the Blind, and chair of the Access and Transportation Committee, was instrumental in formulating the technical specifications used in San Francisco. He can be reached at 916-278-6988 or

A wealth of information and research about APS can be found on the newly redesigned web site of Accessible Design for the Blind at

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Lainey Feingold
Jessie Lorenz
Article Topic
Access Issues