To focus this research, it is important to first look at what vision-impaired
people say about their activity and travel in order to understand if some type
of impedance to access exists, and, if so, if it can be mitigated through increased
spatial knowledge delivered by a location-based auditory modality.
Data collected from two different experiments relating to difficulties that
blind and vision-impaired people face when using transit validate our research
interests and procedures. A previous experiment was conducted with 27
vision-impaired subjects in the mid-size town of Santa Barbara, California.
The only forms of public transit in the city are a bus system, some paratransit,
and cab service. That study produced data about subjects’ perception
of using transit (Golledge & Marston, 1999) . They rated the difficulty
of performing specific transit tasks and some of those data are compiled for
the following table.
Table 2. 1 Transit
Task Difficulty (Santa Barbara)
Golledge & Marst o n, 1999)
Rating scores based on values of “Extremely difficult (1), Very difficult
(2), Difficult (3), Somewhat difficult (4), Not at all difficult (5)”
| “How Difficult Are These Transit Tasks?” | Rating |
| Finding the proper bus stop | 2.4 |
| Finding my way around the main terminal | 2.5 |
| Finding the proper bus among those at the terminal | 2.6 |
| Transferring from one bus to another at the main terminal | 2.6 |
| Transferring to another bus on the line | 2.8 |
| Having to cross busy streets | 3.1 |
| Finding and boarding the proper bus | 3.2 |
All tasks we rated between the range of “Very Difficult” to “Difficult”. Finding a bus stop was rated as the hardest with a rating of 2.4, closer to “very difficult” than to “difficult.” Navigating around a terminal was rated mid-way between “very difficult” and “difficult.”
Finding and transferring buses at a busy terminal were rated almost as difficult as the first two tasks. Transferring buses on the route was not as difficult as at a terminal. Crossing a street and finding and boarding the proper bus was rated close to “difficult.”
A larger and more intensive interview was conducted during this reported research in San Francisco, a much larger city with many forms of public transit.
Table 2.2 shows a wide range of 20 transit tasks listed in the order of the difficulty reported by 30 subjects in the present study. The same rating scale was used as in the first table. These data are discussed later in much more detail (see Section 3.2 , User Rated Difficulty of Transit Tasks ).
In order for the reader to fully appreciate the challenge faced by those persons with visual impairments seeking independent travel, this author challenges the sighted reader to consider how easy these tasks are with vision and then try to imagine what they would be like without sight. These two tables, which show how difficult these tasks are, highlight the important nature of this research. Again, the ratings fall between “Very Difficult” and “Difficult”. With this degree of difficulty, independent travel in a safe and timely manner is denied to many vision-impaired people. Hence, for this group, the city needs to be made more accessible.
Table 2. 2 Transit Task Difficulty (San Francisco)
Rating scores based on values of “Extremely difficult (1), Very difficult
(2), Difficult (3), Somewhat difficult (4), Not at all difficult (5)”
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