BUS STOP LOCATOR: AN APPLICATION OF AUDIBLE SIGNAGE TECHNOLOGY

Donna Jo Therrien, Stephen Tippin, Chris Groff, and Steve Belcher Wright State University, Department of Human Factors and Biomedical Engineering Dayton, Ohio

Abstract

The Bus Stop Locator, a device used to assist people with visual impairments in locating, traveling to, and finding out information about bus stops, is described. Problems encountered by people with visual impairments in accessing and using public transportation are given. The limitations of proposed and developed audible signage technology are discussed. Results of preliminary trials and planned modifications for this design are given.

Background

According to the Bureau of the Census, 9.7 million people in the United States are unable to read printed signs at normal viewing distance.1 Additionally, estimates of tested acuity classify 1.1 million people as legally blind (corrected acuity of 20/200 or less or visual field of <20 degrees).2

Visual impairments vary significantly in effects and degrees. Effects of disability may be lessened with education and training. Moreover, individual differences in preferences and education may present challenges for persons and organizations making accommodations for people with visual impairments.

Uses of audible signage to assist people with visual impairments have been proposed and developed. Most employ amplitude modulation (AM) or frequency modulation (FM) radio, inductive loop, or infrared technology. One infrared system (Talking Signs, Inc.) is currently used in San Francisco, California, transit facilities. This system relies on light-emitting diodes to transmit digitally encoded human speech messages. A hand-held receiver picks up, decodes, and plays the message.

Statement of the Problem

The Miami Valley Regional Transit Authority (RTA) in Dayton, Ohio, has developed and implemented comprehensive route training programs to assist people with visual and other disabilities in accessing and using public transportation. However, one of the more vexing problems for bus riders with visual impairments has been locating bus stops in unfamiliar areas.

The Bus Stop Locator is a response to a need communicated by RTA regarding bus stop accessibility for consumers with visual impairments. Currently in the Dayton area, no assistive mechanism exists to enable blind or visually impaired persons traveling in unfamiliar areas to easily locate and access bus stops and route information.

Rationale

For the sighted bus patron, cues as to bus stop location and bus identification are easily distinguished by signs, bus shelters, and other visually distinctive features. To the visually impaired patron, signs and other visual information may provide no assistance, and these people may become lost or involved in possibly dangerous situations because they cannot find bus stops in an easy and timely manner. The risk is increased when people travel in unfamiliar areas or on complicated routes (such as those requiring multiple transfers). Recent accidents involving experienced blind subway and bus riders on their everyday routes have emphasized the need for a more comprehensive accommodation program.3

Often, blind and visually impaired bus riders must depend on others for information regarding bus stop location and bus identification. This situation not only is inconvenient for both parties but also poses significant danger to the visually impaired people who must place themselves at the mercy of strangers. The information given may be less than accurate and complete. Additionally, at night and in less frequented areas, no one may be around to offer assistance. Finally, people with visual impairments simply do not like to be dependent on others for information, especially if suitable alternatives are available.4 Clearly the need exists to assist people with visual impairments in locating and accessing bus stops and basic bus information (street, direction of travel, etc.).

Available and past approaches to audible signage transmit continuously (and thus require continuous power supply), require the user to be in the line-of-sight for activation, are cost prohibitive, require users to wear conspicuous devices, and/or do not make route information available to people without receivers.

Design

The design involved two major needs: a method for the user to interrogate the area for information on the location of a bus stop and a method for the bus stop to inform the user as to its location and provide suitable information about the bus route. The method chosen to interrogate the area consisted of a hand-held, two-channel radio transmitter. At the bus stop, a two-channel radio receiver was used to decode the transmitted signal. The output from the receiver activated either an audio location beacon or a recorded message.

Also included was a push button at the bus stop which activated the recorded message. To meet environmental needs, the specifications called for operation over -30 to 120 degrees F and the ability to withstand driving rain, freezing rain, and snow. The device also needed an operational range of at least 50 feet. It was preferred that the bus stop unit be independent of the power line mains for internal power. Development During development, input was sought from blind persons through the Clovernook Center in Cincinnati, Ohio, and the Wright State University campus. The basic idea was well received. It was made clear by the consumers that the transmitter should be unobtrusive and not call attention to the user.

A commercially available radio transmitter and receiver (Linear) were used. This assured that the system would meet FCC requirements and use proven technology. The transmitter is similar in size to a garage door opener and can be activated from within clothing. The audio location beacon consists of a single-frequency tone (Floyd Bell). For the bus stop information, a digitally recorded message is recorded (ISD) and played back through a weatherproof speaker. Power is provided by a 12-volt sealed lead acid battery. A solar panel is used to keep the battery charged.

A demonstration prototype was built in a hermetically sealed housing, which could be mounted to a pole. To meet temperature requirements for the region, the system was designed to operate from -40 to 140 degrees F.

The transmitter had two buttons providing two different signals to the receiver. One button was labeled with the Braille symbol for "S" (signal), the other was labeled with a Braille "V" (voice). The "S" button triggered the location beacon and the "V" button the recorded message. The beacon would sound as long as the "S" button was depressed. Once triggered, the message continued to the end. The message could be as long as 16 seconds.

Figure 1. Block Diagram for Bus Stop Locator.

Evaluation

The prototype has been presented to the RTA Committee on Regional Transportation Accessibility. The reaction from a blind committee member was very enthusiastic. "When can I have one?" he said. The members representing Mental Retardation/Developmental Disabilities wanted the device for their consumers. The prototype design was tested by RTA and two consumers who are blind at a downtown location for three days in November 1995. The battery operated the unit during this time with no difficulties in temperatures below 20 degrees F. Again, feedback was positive. RTA requested a second testing date in order to allow more users time to analyze the unit. The consumers stated that the device was very useful and provided helpful, directional information to help them locate, travel to, and get information from bus stops. Suggestions for improvement made by RTA included making the signal louder in heavy traffic conditions and tapping into power from the street lights.

Discussion

The demonstration prototype successfully meets the basic requirements. It provides an unobtrusive way for a blind user to activate it. It produces a signal that enables the user to locate the bus stop and a recorded message that informs about route information. The device can be activated without the user being in the line-of- sight of the radio transmission. A push button mounted with the unit provides information to others at the bus stop.

A second prototype is in development that will improve upon the first one. The main consideration is to provide an audio beacon and recorded message that automatically adjust their volume to the environmental background noise level. A disadvantage of most of the available systems is that they do not adjust for ambient volume conditions. When traffic or other background noise increases, volume does not automatically adjust in response. This feature is especially important in the case of bus stop signaling devices, which are frequently around high-traffic areas. By decreasing in volume in response to decreased environmental noise, the device would be less bothersome and distracting to individuals who live or work near the sign or persons waiting at the bus stop.

Other desired changes are: reducing the size of the unit, thereby making it less noticeable to the general public and less of a target for vandalism; building one tone-emitting/messaging circuit; finding more compact solar recharging cells; building in AC/DC power supply options; and developing circuits that require little to no power in standby mode.

A second set of tests will be performed in December 1995 with more consumer trials to get data on battery duration, solar recharging, and temperature response.

While the focus of this project is on visual impairment, a number of other disabilities negatively impact a person's ability to read and interpret printed material: stroke, head injuries, autism, mental retardation, dyslexia, and illiteracy. Thus, the disability assisted by the Bus Stop Locator may be described as any number of conditions that inhibit or prevent a person from reading and interpreting visual information.

References

1. McNeil, J., "Americans with Disabilities: 1991-92," U.S. Bureau of the Census Current Population Reports, Washington, D.C.:U.S. Government Printing Office, 1993.

2. Chiang, Y-P et al, "Federal Budgetary Costs of Blindness," The Milbank Quarterly, 1992, 70(2).

3. "Transit Facility Design for Persons with Visual Impairments," United States Architectural and Transportation Barriers Compliance Board, 1995. [on-line resource]

4. Crandall, W., Ph.D., et al, "Talking Signs Remote Infrared Signage: A Guide for Transit Managers," The Smith-Kettlewell Eye Research Institute, 1995.

Acknowledgments

The authors wish to thank the principal advisor Dr. Blair Rowley, Ph.D., and the graduate students in rehabilitation engineering at Wright State University for their work in the preliminary design and development.

Donna Jo Therrien 228 Liberty Street Dayton, Ohio 45402 (513) 331-9029 email: s004djt@discover.wright.edu