Research on Speech Messages
The Accessibility Guidelines for Pedestrian Facilities in the Public Right-of-Way (PROWAG) (1), published August 8, 2023, introduced new requirements for speech messages communicating the operating mode of traffic control indications under two conditions. These requirements are intended to make signal information accessible to and usable by people who are blind or who have low vision:
R307.8.4 Locator Tone and Traffic Control Signal in Flashing Mode. When the traffic control signal is operating in a flashing mode, pedestrian push button locator tones shall remain active, and the pedestrian push button shall activate a speech message that communicates the operating mode of the traffic control signal.
R307.7 Audible and Vibrotactile Indication for Pedestrian Activated Warning Devices Without a Walk Indication. Where a pedestrian push button or a passive detection device is provided for pedestrian activated warning devices, such as rectangular rapid flashing beacons, the pedestrian push button or passive detection device shall activate a speech message that indicates the status of the beacon in lieu of an audible walk indication. The speech message volume shall comply with R308.4.
No specific messages are included in the requirements for either traffic control condition; therefore, Accessible Design for the Blind engaged in research to identify speech messages for use in each of these two conditions that best helped PVD to understand what signal information was being provided to sighted pedestrians and to drivers, and what information would reliably result in safe crossing decisions. The research, findings, conclusions, and recommendations are reported in the following document which begins with an executive summary, and further provides a full report of the research:
Tactile Walking Surface Indicators
Tactile Walking Surface Indicator (TWSI) a generic term now used in the United States for three types of walking surfaces used to aid wayfinding by pedestrians who are blind or who have low vision. TWSIs have been a focus of research in the U.S. for more than 30 years, beginning with study of truncated dome detectable warning surfaces (DWS), then study of raised bar tactile direction indicators (TDI), and most recently study of trapezoidal tactile warning delineators (TWD). While standards and requirements already exist for the design and application of DWS, recent years have brought emerging recommendations and guidance for the combined use of all three types of TWSI in a coordinated manner to produce more comprehensive accessible wayfinding information in a variety of environments.
The following documents are a white paper introduction to tactile walking surface indicators, a presentation on TWSIs that includes short summaries of some of the relevant research, a video showing a pedestrian with a vision disability navigating a street crossing near a roundabout without and with tactile direction indicators, and a link to the free-to-download pre-publication draft of TCRP Research Report 248 (Tactile Wayfinding in Transportation Settings for Travelers Who Are Blind or Visually Impaired). The report includes a comprehensive literature review regarding TWSI, a full report of project research activities, and a guidebook on the application of TWSI in a variety of environments. If you are prompted to enter a password when opening the PowerPoint presentation, select the “Read Only” button and the file will open without the need of a password.
Tactile Walking Surface Indicators: What are they, and where should they be used?
PowerPoint presentation on tactile walking surface indicators and select research