Purchase this article with an account.
S. E. Hassan, G. D. Barnett, A. Moore, R. W. Massof; Are Pedestrians Able to Make Correct Street-Crossing Decisions Using Only Auditory Information?. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4721.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Even though the street environment is both a visually and auditory rich environment, blind pedestrians have shown that one can make street-crossing decisions based on auditory information alone. Little is known however how reliable these decisions are. The aim of this study was to determine the accuracy of normally-sighted, visually impaired and blind pedestrians at making correct street-crossing decisions using only auditory information.
Using a 5 point rating scale, safety ratings for vehicular gaps of different durations were measured along an unsignalized, two-lane street of one-way traffic. Safety ratings were collected from 12 normally sighted, 10 visually impaired and 10 blind subjects for 8 different gap times under the sensory test condition of hearing only. A subject’s street crossing decision was classified as being "safe" when the subject’s street crossing time was less than the gap time. The converse was true for "unsafe" street crossing decisions. The percentage of correct street crossing decisions (ie. correctly identifying "safe" and "unsafe" trials) was determined for each subject group and gap time.
We found that blind subjects made significantly more incorrect street crossing decisions compared to either the normally-sighted or visually impaired subjects for gap times that were between 2, 3 and 4 seconds shorter than the minimum time required for a safe crossing (p<0.05). For gap times that were up to 1 second shorter than the minimum crossing time, the performance of the normally sighted subjects dropped significantly from that of the visually impaired subjects (p=0.01) to a level similar to that of the blind subjects (p=0.57). No significant differences in performance were found across subject groups for gap times that were longer than the minimum time required for crossing (p>0.05).
Our data suggests that pedestrians can use auditory information to make appropriate street crossing decisions, but its reliability depends on how far away the approaching vehicle is from the pedestrian. Our finding that blind pedestrians performed significantly worse than either the normally-sighted or visually impaired subjects for certain unsafe vehicular gap times, suggests that they may benefit from training to improve their detection ability and /or interpretation of vehicular gap times.
This PDF is available to Subscribers Only