Presented at the 1993 meeting of RESNA.
With the passage of the Americans with Disabilities Act (ADA), questions arise as to how the environment should be labeled for blind and visually impaired travelers. During the rulemaking process a question raised by the Architectural and Transportation Barriers Compliance Board (ATBCB) for public comment stated, in part (Question 13), "In areas where overhead signage is typically provided such as conference centers and bus stations, how can information on these signs be made accessible to persons who use raised and Brailled characters?" (Federal Register, January 22, 1991). As a result of written and oral testimony given before the ATBCB by our institute, the final Rules and Regulations (Federal Register, July 26, 1991) stated that "Although technology is available for making overhead and remote signage accessible, the Board plans to further study this issue to determine where and in what type of buildings and facilities such technology may be necessary for future revisions of the guidelines." No doubt, various systems (radio, inductive loops, infrared and satellite navigation) will be considered.
This paper does not deal with the general issue of accessible signage for persons who are blind or otherwise print-handicapped. Rather, it discusses remotely accessible signage -- signs which do not have to be specifically approached to be read -- a technology which is most consistent with the conventional signs available to nondisabled individuals.
Specifically, remote signs allow people to directly know not only what, but where. Just as sighted persons visually scan the environment to acquire both label and direction information, remote signs directly orient the person to the labeled goal and constantly update the person as to his progress to that goal. That is, unlike Braille, raised letters, or voice signs which passively label some location or give mobility instructions to some goal, the remote signage technology developed at our institute provides a repeating, directionally selective voice message which originates at the sign and is transmitted to a hand-held receiver. The direction selectivity is a characteristic of the infrared message beam and ensures that the person using the device gets constant feedback about his relative location to the goal as he moves towards it.
What other characteristic of signs are valuable to the traveler? Mainly, signs provide identification. However, in the broadest sense, signs comprise a menu of choices for the traveler; they confront him with the options available to him at any given point in his travels. In a sense, signs act as a form of memory for the traveler; they "remind" him about important characteristics of the environment. In transit situations, the sighted traveler receives adequate preview of vehicle arrival and he knows which buses/trams or stops are irrelevant to him. Early identification of distant objects (buses or stops) is an especially important attribute of an effective remote signage system.
Street signs can serve as a simple and revealing example of how signs are used. What do sighted people know as they approach an intersection? They know the names of the streets; they know the block number, which orients them in the city's scheme of things; they see the presence of a crosswalk or the lack of one; and white lines tell them crosswalk directions. Observing traffic patterns and noting the presence of walk/wait signs, they know if the intersection is controlled by a signal; they also, with a quick glance, determine whether or not the signal is controlled by a pushbutton.
What do blind people know as they approach an intersection? They know by listening to traffic patterns whether or not the intersection is controlled by a traffic signal. Where intersections involve three or more streets, the listener can at least determine that it is a complex intersection. By noting the direction of signal-controlled traffic, the times when it is permissible to cross can usually be determined. The blind traveler may not notice the pushbutton if there is one. Like the print-handicapped, the blind traveler may not know the name of the street he is crossing. To learn an address number, he must find an open establishment and ask the proprietor.
The infrared transmitter and photodetecting receiver developed at our institute became a product of Love Electronics called Talking Signs®. They go beyond the concept of mere indicators; they are full-featured information systems. Recognizing this, Mr. Gordon Chester of the San Francisco Department of Parking and Traffic specified a design for Talking Signs® which would give the user six pieces of information:
1. The name of the cross-street can be heard through the user's receiver. (The name of the street parallel to his direction is heard when the receiver is pointed across that street.)
2. The address number of the block ("zero hundred block," "100 block," etc.) is also announced through the user's receiver.
3. Since Talking Signs® use directed beams of infrared light, the direction in which the user's receiver is pointing is also announced (facing southwest, for example).
4. The "color" of the light controlling the traffic is announced ("red," "green," or "yellow").
5. The crosswalk information is transmitted via a narrow beam which is confined to the boundaries of the crosswalk. Therefore, when red, green, and yellow information is heard, the traveler knows that he is in the crosswalk.
6. By scanning the receiver left and right, the precise direction along the crosswalk is indicated; the user searches for the clearest signal.
The City of San Francisco has installed eighteen Talking Signs® units of the above specifications at busy downtown pedestrian intersections.
Another consideration in choosing aids for the blind traveler is the intrusion caused by their presence. Where audible traffic signals have existed (such as San Francisco's early crosswalk experiment, which used a bell and a buzzer), residents have insisted that they be turned off at night. At the very least, they draw needless attention to the accommodation made for the blind traveler.
The receiver of the Talking Signs® system is a personal listening device. Its small speaker is in the hand of the user and causes no high-volume signal to be produced for others to hear. Furthermore, if the traveler is familiar with all aspects of an intersection which he uses regularly, he may choose not to actuate the receiver at all, but to depend on standard mobility skills to negotiate the intersection.
Because Talking Signs® speak the names of streets and address numbers, they address the needs of the print-handicapped as well. Other services, such as closed-circuit newspapers by radio and the Talking Book library, have expanded to their current levels because of their use by the print-handicapped.
Our institute has made its infrared remote signage technology available in the public domain in the form of Braille, cassette, and computer disk (1).
The following technical specifications are for those familiar with communications theory: