History of APS in the U.S.

APS but no regulations

Although there are reports of audible pedestrian signals in the U.S. as early as 1920, they were not included in U.S. standards and regulations until MUTCD 2000.

Figure 1-2. Pedhead-mounted APS; APS speaker mounted on top of pedestrian signal head

APS first mass marketed

Mid 1970's

Controversy over their use

For early installations, there were complaints about noise of the signals from residents living near installations.

In addition, there was disagreement about the need for APS between two main consumer groups of blind people, American Council of the Blind and National Federation of the Blind. Until the early 1990's:

While each of these consumer groups have a membership of approximately 25,000 people which combined represents less than 1% of people who are blind or who have low vision in the U.S., this disagreement was often very confusing to community officials. While the NFB has now stated that APS should be used in some situations, they are still opposed to "wholesale" installation at every intersection.

Problems with pedhead-mounted APS

See Appendix C for detailed information on research results.

Pedhead-mounted APS provide limited information:

Figure 1-3. Pushbutton-integrated APS

Newer types of APS available — Pushbutton-integrated

In the mid-1990's, APS that were integrated into the pushbutton, based on the European and Australian systems, began to be available in the U.S.

These APS provide audible indications from the pushbutton at a generally quiet volume, intended to be heard 6 to 12 feet from the pushbutton.

Additional features include

Proper location is essential

The functioning of pushbutton-integrated APS is based on proximity to the crosswalk location. The closer the APS is located to the departure location, the quieter it can be. In addition, the vibrotactile indication and tactile arrow are not usable when located too far back from the street. Figure 1-4 illustrates installation recommendations.

Figure 1-4. Ideal Installation — Within 5 feet of the crosswalk extended, within 10 feet of the curb, and separated by more than 10 feet from other APS on the corner, adjacent to a level landing

Changes in intersection design, traffic and signalization

Changes in intersection design, traffic, and signalization have affected the ability of pedestrians who are blind to cross streets using traffic sounds, as discussed in detail in Chapter 2.

APS currently available in the U.S.

APS provide an auditory (tone or speech) indication of the WALK interval. Vibrotactile indication of the WALK interval is required by the Draft PROWAG, but not all APS devices are capable of providing vibrotactile indications. Numerous other features are available and detailed descriptions of the various features can be found in Chapter 4.

In the previous version of this document (Accessible Pedestrian Signals: Synthesis and Guide to Best Practice), APS were described as one of four design types: pedhead-mounted, pushbutton-integrated, vibration-only, and receiver-based. These device design types were mainly categorized by the location and type of WALK indication provided, although there were characteristic differences in other features at that time. As technology has developed, several combinations of these different types have emerged, and modifications have been made that prevent easy separation of devices into four 'types'. The discussion of APS and their features using those terms becomes confusing. This Guide, Draft PROWAG, and the MUTCD all recommend APS that have audible and vibrotactile WALK indications, which are only available when APS are integrated into the pushbutton. However, other features, such as additional beaconing speakers, may also be provided.

In this Guide, other than this chapter and Chapter 9, the labeling of types of APS has generally been dropped. These types are described here for clarification, as background information. Some manufacturers or distributors may continue to use these terms to describe available products.





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