The thrust of the current NIDRR research program was to evaluate the effectiveness of remote infrared signs in solving current and emerging access problems of people who have disabilities that prevent them from reading print. The program focused on three main areas:

• Street Crossing Information
• Transit Facility Accessibility for People with Developmental Disabilities
• Emergency Egress Information in Buildings

The progress we have made towards solutions to these problems is summarized below:

Part I: Street Crossing Information
Crossing points are the places in any journey where the traveler is most vulnerable to disorientation and danger in the form of collisions with passing vehicles which can result in serious injury or death. At signalized intersections in busy urban areas, many confusing cues are presented to the blind traveler who must rely primarily on traffic sounds to determine the geometry of intersections, the nature of traffic control, the direction o head to reach the destination corner, and when it is safe to cross.

Progress has been made in clarifying many of these ambiguities through the deployment of specially adapted prototype remote infrared signage (Talking Signs®) units at signalized intersections in downtown San Francisco. The special transmitters provide two types of messages to pedestrians. The first tells the user where he or she is located; it is comparable to the information posted on the visual street signs at each intersection. The second type of message, presented when the user nears the curb, tells users the condition of the pedestrian signal. It repeats, for example "Wait... Larkin Street" or "Walk Sign.... Larkin Street," the particular message depending upon the status of the visual walk/wait sign.

Our human factors study showed that this remote infrared signage at intersections significantly improved safety, precision, and independence in street crossing, as well as knowledge of intersections. Improved performance was noted for good, frequent, independent blind travelers, using a long cane or dog guide, and also for persons who considered themselves relatively poor travelers who did not normally travel in unfamiliar areas. Persons with mild to moderate hearing loss were also successful in using Talking Signs to facilitate street crossing.

Take me directly to Part I without further delay!

Part II: Transit Facility Accessibility for People with Developmental Disabilities
Although the primary focus of our research has involved blind and visually impaired persons, there is a very significant population of persons who, because of other disabilities, do not have access to the print signage so essential for navigating and accessing public and private facilities. Conversely, the he over abundance of information in the environment works against the independent travel of people who are developmentally disabled. Therefore, it is important to have unambiguous travel information available at appropriate places along the path of travel.

Pilot experiments in San Francisco and Philadelphia showed that remote infrared signs can enhance the independence of people who are developmentally disabled. People who are not able to read print signs were able to auditorily identify destinations through Talking Signs messages. The repeating messages also gave people who are cognitively impaired the opportunity to study the message repeatedly until they could decide whether the information was relevant. Talking Signs provide menu of choices and reminders for cognitively impaired traveles — signs confront them with the options available at any given point in their travels and remind them where to go next. The Signs Signs are directional, so that the traveler can "look around." Once the appropriate destination is recognized, the traveler can move in that direction.

The Talking Signs system is an excellent aid to travel for persons with developmental disabilities. It can enable them to independently confirm the location and identity of key features in a transit station such as the correct faregate, the correct side of a platform, or the correct exit from a platform or station to a street or to a connecting bus or train. The best uses of the Talking Signs technology for persons with developmental disabilities are expected to be labeling transit facilities, identifying transit vehicle destinations and providing next stop messages.

The present study led to the conclusion that Talking Signs appears well adapted to aiding travel for persons with developmental disabilities. Its best use for this population is expected to be confirming travel decision points by labeling such items as transit facilities, including transit vehicles identification, next stop messages, faregates, platforms, or the correct exit from a platform or station to a street or connecting bus or train. Training should be integrated with a regular program of travel training for this population.

Take me directly to Part II without further delay!

Part III: Emergency Egress Information in Buildings
The problem of providing emergency egress information to individuals who are visually impaired is complex because emergency procedures vary according to the type and extent of emergency, size of building (single floor or highrise), occupancy (i.e., hotel or office building) and type of building construction (i.e., fire and smoke secure guest rooms and/or stairwells). The California State Fire Marshal conducted a nationwide survey in 1998 to determine how other states had approached this problem and found that no state had promulgated laws or rules in this area.

In order to model the effectiveness of communicating emergency information in a number of accessible formats, a paradigm was established where subjects read or listened to instructions for traveling an indoor route to an exit stairway, and then were asked to travel to that stairway. Specifically, the "goodness" of communication effectiveness was determined by objective and subjective measures for each of the following five accessible formats that provided them with information enabling them to reach the exit stairways: Braille, raised print, tactile maps, push button audible signs and remote infrared signage (exemplified by Talking SignsR).

This study concluded that, of the options studied, both remote infrared audible signs and push-button audible route directions gave by far the best performance (i.e., they were far superior in all measures), enabling users to access emergency egress information efficiently. Formats other than the ones evaluated in this study may be as effective or more effective; however, each should be subject to scrutiny through research techniques as employed in the present study.

Take me directly to Part III without further delay!

Background to the three studies
Impetus for the Present Research
Technologies for independent travel
References for Preface

Background to Studies

The National Center for Health Statistics estimated that 4.3 million people in the US have difficulty reading the newspaper with their corrected vision -- a functional definition of perceived limitations termed Severe Visual Impairment (1). Importantly, an additional 2.3 million people have a disability that involves the loss of intermediate or distant vision. From these statistics, we may conclude that a total of 6.6 million people may be unable to read printed street signs or signage inside buildings at normal viewing distance. Data from the Bureau of the Census put the figure for this same level of impairment at 9.7 million people (2). There is another important way of looking at the demographics of blindness. Estimates of tested acuity classify 1.1 million people as Legally Blind which is defined as corrected acuity of 20/200 or less and a visual field of < 20 degrees (3).

Many other disabilities prevent persons from reading print. In addition to people who are blind or have low vision and may not be able to see the print, there are many stroke, head-injured, autistic and dyslexic (or even just educationally impaired) persons who may not be able to assimilate printed language even though they can see the page. Many people can accept this information through speech -- having print read aloud to them.

Impetus for the Present Research

Although the various technologies described above have been variously proposed and prototyped, when the present research program began there had been few attempts to evaluate objectively the performance of such systems in real world settings. The purpose of the present study was to develop and evaluate versions of remote infrared signage designed for specific real world applications such as street crossings, transit facilities access and emergency egress from buildings. The human subjects data thus gained could be used to further the development and refinement of orientation systems for blind persons and those with cognitive and other disabilities.

Technologies for independent travel

In modern society, independent travel is a prerequisite to successful education and employment. For blind persons, independent travel involves not only finding a safe path through the environment, but being able to find landmarks and orient oneself. For blind persons, these tasks are challenging and have been the subject of many efforts to develop assistive technology to make some or all aspects of travel easier. The following is a summary of these developments.

Mobility Devices

Technology to assist blind travelers can conveniently be categorized as Orientation devices and Mobility devices. Historically, most efforts focused on the mobility part of the problem – helping the blind traveler to detect objects, hazards and boundaries in, near or alongside his path, avoid collisions, and steer a straight and safe course through the immediate environment. A family of mobility aids known as Electronic Travel Aids or ETAs has resulted. These vary from simple obstacle detectors to more complex environmental sensors. For example, the Mowat Sensor is a hand-held ultrasonic device that uses a vibratory code to warn of the presence and range of an object in its beam. At the other end of the spectrum is the head worn Sonicguide, which processes broad band ultrasonic reflections so that the pitch of the received signal indicates range, the timbre indicates the nature of the target, and the inter-aural amplitude difference indicates direction. The Laser Cane uses laser beams to detect objects, and incorporates the ability to warn of drop-offs. Another mobility aid is the Sonic Pathfinder, the subject of another paper in this issue.

Orientation and Navigation Devices
Technology to address the broader orientation and navigation aspect of the Orientation and Mobility (O&M) problem has a shorter history, and devices in this category have only recently entered commercial production. The infrared Talking SignsR system reported on here was developed as an environmental labeling system to allow blind travelers to locate and identify landmarks, signs, and facilities of interest in the environment. It uses speech messages stored in infrared transmitters as labels, and the user’s hand held receiver converts the transmissions back into speech. The infrared beam pattern provides control of range and coverage, and the directional nature of infrared light allows the user to accurately locate each sign.

Since this concept was put forward in 1979, a number of other technologies have been proposed for the orientation problem, though only infrared signage systems are currently available. The Sonic Orientation and Navigation Aid (SONA), a prototype environmental labeling system with sound sources triggered by a garage door opener transmitter was developed by the VA concurrently with Talking Signs (4). Variants of this concept using speech labels triggered by a user carried device include the REACT system (5), The Open University device (6), and the Acrontech International system.

A number of systems using radio transmission of speech messages to receivers carried by the user have been proposed. Verbal LandmarkR demonstrated a system in 1993 in which a portable receiver detects messages transmitted from an electromagnetic loop. The Fanmark "Locator", advertised in 1993, employed consumer receivers to pick up digitally recorded voice messages on an unused FM band. A proposed Chico system (7) would use transceivers triggered by a user-carried speech output transceiver. A proposed NYNEX system (8) would employ a "grid" of radio frequency transmitters located on tall structures and street corners, to which the user would orient and triangulate using a directional receiver and headphones.

Several projects have explored GPS applications for assisting orientation. Loomis (9) has systematically studied this possibility combined with externalized sounds for locating environmental features. A derivative of this approach has been developed by Arkenstone Inc. (10) whose prototype uses a notebook computer packaged with the GPS and synthetic speech in a backpack. A GPS enhancement was proposed for the Nynex system, with speech recognition to respond to user inquiries. The RNIB MoBIC (Mobility of Blind and Elderly People Interacting with Computers) project (1994-96) used GPS technology and proposed a protocol, based upon ISO’s Open Systems Interconnection architecture (1978), to interface different technologies that could be used for orientation and navigation (11).

An infrared system (“Pathfinder,” modeled on the Talking SignsR system) is currently being evaluated in a London subway station (12). The OPEN (Orientation by Personal Electronic Navigation) project set out to investigate the feasibility of a “networked” multilingual system of infrared transmitting signs (1994) incorporating real time information for subway applications (13).

Intersection-Specific Technology

Accessible Traffic Signal systems are gaining prominence with at least eleven products readily available to cities. These devices variously provide information about the light cycle; the street name and direction of travel; street geometry; location of the pedestrian crossing actuator; and location of the opposite corner (14). Devices can be audible, using speaker or infrared transmission to communicate by way of spoken messages, tones or other unique sounds. Other devices are tactile with either raised lines to communicate properties of the intersection or vibrators to indicate the light cycle. Perhaps the greatest improvement in the traditional audible speaker system is circuitry, which automatically adjusts the output volume depending upon the ambient sound level.

These projects were supported by the National Institute on Disability and Rehabilitation Research and by The Smith-Kettlewell Eye Research Institute's Rehabilitation Engineering Research Center.

References for Preface

1. Nelson, K., Dimitrova, E. Severe visual impairments in the United States and in each state. Journal of Visual Impairment and Blindness. 1993;87(3):80-85.

2. McNeil, J. Americans with Disabilities: 1991-92. U.S. Bureau of the Census. Current Population Reports, U.S. Government Printing Office, Washington, DC. 1993;70-33.

3. Chiang, Y-P, Bassi, L, Javitt, J. Federal budgetary costs of blindness. The Milbank Quarterly. 1992;70(2):319-340.

4. Kelly, G.W. (1981). Sonic Orientation and Navigational Aid (SONA). Bulletin of Prosthetics Research,1, 189.

5. Whitney, G., Overview of REACT. The Use of terminals by visually disabled persons, J.M. Gill and C. Rundel, eds. Royal National Institute for the Blind, Technical Development Report no. 2, London; 1987.

6. Jones, D. Talking Signs: The sound of things to come. New Beacon. October, 1991;75(891).

7. Main, R. Intelligent sensing device for improving mobility for the blind. Proceedings: CSUN Conference on Technology and Persons with Disabilities. March 20-23, 1991:589-604.

8. Urband, E., Stuart, R. Orientation enhancement through integrated virtual reality and geographic information systems. Proceedings: CSUN Virtual Reality and Persons with Disabilities. March 18-21, 1992:55-62.

9. Loomis, J., Golledge, R., Klatzky, R., Speigle, J., Tietz, J. Proceedings of the First Annual International ACM/SIGCAPH Conference on Assistive Technologies. Marina Del Rey, California, Oct 31 – Nov 1, 1994. New York: Association for Computer Machinery; 1994:85–90.

10. Rank Prize Funds Symposium on Technology to Assist the Blind and Visually Impaired. Grasmere, Cumbria, England; March 25 – 28, 1996.

11. MoBIC Consortium (1997). Mobility of blind and elderly people interacting with computers. Royal National Institute for the Blind, London; 1997.

12. Design Insight. Joint Mobility Unit, Royal National Institute for the Blind. Spring, 1998;1(9).

13. Gallon, C., Stephens, R., Whitney, G., “The wayfinding requirements of blind of partially sighted people in metropolitan underground railways.” Proceedings: TIDE Congress, Paris; April, 1995.

14. Bentzen, B.L. and Tabor, L.S., Accessible Pedestrian Signals. U.S. Access Board, Washington, DC; 1998.