Electronic travel aids (ETA) have been developed to extend the very limited preview range of the long cane or guide dog used by many who lack vision. Some of these aids do not adequately provide the missing environmental cues, because the role of vision in navigation, and how to substitute for it, is not well understood. (Brabyn, 1985) raised the following questions. What are the essential components of information needed for orientation? What spatial cues does a sighted person rely on for maintaining a safe course through the environment? How can environmental cues be coded and transmitted to a person without vision? .
Most blind people receive some type of Orientation and Mobility (O&M) instruction. What is also needed is the means to access knowledge that gives information helpful in the spatial task of orientation or wayfinding. The standard travel aids for the blind assist in mobility, and they work as barrier or obstacle avoiding aids. However, they are not very useful for gaining environmental knowledge (orientation) that allows for exploring new routes and environments or making shortcuts. A GPS and GIS based Personal Guidance System (Loomis, Golledge, & Klatzky, 1998) , developed at the University of California, Santa Barbara, can transmit spatial information to assist in orientation, making it a big advancement over aids that only help with mobility. Research on the ability of vision-impaired people to use complex spatial locational and relational information is required to better understand the role of vision and how to provide this information to the blind (Golledge, 1993) .
To date, there is little understanding of the functional barriers that discourage travel and access to the urban environment for those who lack vision. Structural barriers that limit access for people who use wheelchairs have been widely studied and are much simpler to define and identify. They include, for example, curbs, stairs, steep inclines, and heavy doors. Mitigation costs can be estimated with little problem, based on decades of engineering and public works experience. For these structural barriers, one can easily compare the path of travel for the general public against those routes required for a person using a wheelchair in order to determine the “penalties” imposed on these users (Church & Marston, in press; Okunuki, Church, & Marston, 1998) .
However, identifying specific problems that reduce access for the blind is not simply the difference between sighted and blind travel route efficiency and effort. Because of fears about personal safety, concerns about uncertainty, and obstacles in the environment, blind travel will probably always have extra effort factored into it. The major research objective addressed here is to determine the effects on accessibility when vision-impaired people use their regular method as opposed to using auditory spatial cues. A spatial information aid, Remote Infrared Audible Signage (RIAS) known as Talking Signs® (TS) was used in this experiment. This dissertation reports on an experiment that tested if blind and vision-impaired people can perform travel tasks more efficiently, in less time, and with fewer errors when auditory directional and identification cues are provided, and, if this is the case, will they be able to:
In other words, given auditory signage assistance, can they travel through transit space with more efficiency, can they have a higher quality of access to the opportunities of urban life through more efficient travel, and will they feel more confident and enjoy the task of travel? These research questions are addressed in this experiment, and the penalties that vision loss creates in accessing urban opportunities are determined by comparing blind individuals’ RIAS performance to that when using regular methods of guidance. With the use of auditory signage, skilled vision-impaired travelers can be used to determine some of the barriers to independent travel, to provide information to gauge the impact of vision loss on accessibility, and, perhaps, to determine if additional environmental cues can help mitigate these barriers to independent travel for those lacking vision. This research report is designed to provide needed information to regulators, transportation designers, and technologists as to the specific problems experienced by visually impaired travelers and to specific solutions to these problems.
The secondary objectives of this research are to determine how:
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