W. Crandall, Ph.D, B. Bentzen, Ph.D, L. Myers, M.Ed.

INTRODUCTION

Everyone's effective mobility depends upon proper orientation; for mainstream society this is accomplished by printed signs. People who are print disabled, are blind, or have other visual impairments are at a disadvantage for the lack of labels and signs. Talking Signs, the infrared remote signage system developed at the Smith-Kettlewell Rehabilitation Engineering Research Center, provides a solution to this need by labeling the environment for distant viewing -- this system tells people about their surroundings.

The Talking Signs system is comprised of infrared transmitters which convey speech messages to small receivers carried by blind travelers. Infrared transmission is directional. This means that when blind Talking Signs users pick up a message, they can also tell where it comes from. The message is coming from the direction in which they are pointing when they hear the message clearly. Travelers who are blind can get to the destination by walking in the direction from which they receive a clear message. They do not need to remember directions. They just travel toward the sign they hear, in the same way that sighted people travel toward a sign or landmark they see. During the last three years of human factors research we have established that blind people traveling in a variety of environments using Talking Signs can easily learn to use the system effectively.

The system is an information system -- it is not a safety system. It is not a substitute for travel aids such as the long cane or dog guide, or for the use of other sensory information or good spatial reasoning.

The application of Talking Signs at intersections involves providing two types of information to pedestrians. The first tells the user where he or she is located; it is comparable to the information posted on the visual signs at each intersection. The repeating message users hear from the speakers of their hand-held receivers when they are walking down the sidewalk is, for example, "Traveling East on the 800 block of Grove Street toward Larkin Street." When users near the curb, another message is heard through the receiver's speaker. This "pedestrian crosswalk indicator" message tells users the condition of the traffic 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.

Participants completed the experiment individually, in sessions lasting approximately 90 minutes. Participants received approximately 10 minutes of training in using Talking Signs at intersections before completing the experimental procedure.

The following types of data were obtained by an experimenter as each participant made each crossing.

Safety:

1. Did the participant begin the crossing during the Walk phase of the light cycle?

Precision:

2. Did the participant begin the crossing from within the crosswalk?

3. Was the participant heading toward the opposite corner when he/she began the crossing?

4. Did the participant end up within the crosswalk at the opposite corner?

Need for assistance:

5. Did the participant need (request) assistance in finding the crosswalk?

6. Did the participant need (request) assistance in knowing when the walk phase began?

7. Did the participant need assistance in safely completing the crossing (either participant's request, or at the initiative of the experimenter when participant was endangered)?

Knowledge:

8. Did the participant know the general shape of the intersection (plus, T, or irregular)?

9. Did the participant know the nature of traffic control at the intersection (traffic light, stop sign, or uncontrolled)?

Additional objective and subjective measures were also obtained.

Participants were more successful on eight of the nine measures when using Talking Signs than when not using Talking Signs. Nineteen of 20 participants were more successful when using Talking Signs than when not using Talking Signs. One participant had the same (nearly perfect) score both with and without Talking Signs. Participants included persons using both long canes and dog guides, persons with and without hearing loss, persons who considered themselves to be good to excellent travelers, and persons who did not consider themselves to be good travelers.

The following percentages will give the reader some indication of the nature and magnitude of differences in street crossing performance with and without Talking Signs.

	Talking Signs	No Talking Signs
Began crossing during the Walk phase	99%	66%
Started within crosswalk	97%	70%
Started from a heading toward opposite corner	80%	48%
Reached opposite corner within crosswalk	76%	56%
Found crosswalk with no assistance	99%	81%
Identified Walk phase with no assistance	100%	76%
Crossed street with no assistance	97%	81%
Knew shape of intersection	86%	46%
Knew type of intersection control	84%	50%

It appears that Talking Signs at intersections significantly improved safety, precision and independence in street crossing, as well as knowledge of intersections, for good, frequent, independent blind travelers, using a long cane or dog guide, including those with hearing loss. Talking Signs also resulted in improved street crossings for persons who considered themselves relatively poor travelers, and who did not normally travel in unfamiliar areas.

A final report will be issued at the completion of data analysis.

Acknowledgements:

This research was funded by California Pacific Medical Center's Smith-Kettlewell Rehabilitation Engineering Research Center and the National Institute on Disability and Rehabilitation Research and was conducted in collaboration with Intersection Development Corporation of Fullerton, CA, the City of San Francisco Department of Traffic Engineering, and Talking Signs, Inc. of Baton Rouge, LA.