The independence of people with little or no sight is greatly affected by their
restricted access to information, environmental cues, and safe walking.
Since ancient times, blind people have been depicted walking with a stick, sometimes
as a gift from the gods (Levy, 1872/1949) . The Bible curses those who “maketh
the blind to wander out of his way” (Deuteronomy 27:18) and warns that “thou
shalt not put a stumbling block before the blind (Leviticus 19:14). Over
a hundred years ago, Levy, who was blind, offered this striking observation about
independence and mobility: “The importance to every blind man of acquiring
the power of walking in the streets without a guide can scarcely be exaggerated.
Loss of sight is in itself a great privation, and when to it is added the
want of power of locomotion, the sufferer more nearly approaches the condition
of a vegetable than that of a member of the human family” (Levy, 1872/1949,
p. 106) . In more modern terms, Golledge (1993) says that, second only to
the inability to communicate through reading and writing, the inability to travel
independently and to interact with the wider world is one of the most significant
handicaps facing the vision-impaired. Navigation without sight usually
means staying on known or learned routes. Independent exploration off these
learned paths can easily lead to panic, fear and even danger or death when a person
becomes disoriented.
This chapter’s background review points out the problems that a vision-impaired
person faces in gaining access to urban opportunities and the shortcomings of
current accessibility measures in determining barriers and the impedance to access
caused by lack of vision. Previous research was examined that led to the
current experiment design. This design allows for a quantitative measurement
of accessibility and provides specific data that will help improve our understanding
of the difficulties, affective states, and environmental placements that lead
to travel barriers for this population.