The purpose of this study was to measure the accuracy and reliability of normally-sighted, visually impaired and blind pedestrians at making street-crossing decisions using visual and / or 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 twelve normally sighted, ten visually impaired and ten blind subjects for eight different gap times under three sensory conditions: (i) visual + auditory information; (ii) visual information only; and (iii) auditory information only. Accuracy and reliability in street-crossing decision making were calculated for each subject under each sensory condition. It was found that normally-sighted and visually impaired pedestrians were accurate and reliable in their street-crossing decision making ability when using either vision + hearing or vision only (p>0.05). Under the hearing only condition, all subjects were reliable (p>0.05) but inaccurate with their street-crossing decisions (p<0.05). Compared to either the normally-sighted (p=0.018) or visually impaired subjects (p=0.019), blind subjects were the least accurate with their street-crossing decisions under the hearing only condition. The data suggests that visually impaired pedestrians can make accurate and reliable street-crossing decisions like those of normally sighted pedestrians. When using auditory information only, all subjects significantly over-estimated the vehicular gap time. The finding that blind pedestrians performed significantly worse than either the normally-sighted or visually impaired subjects under the hearing only condition suggests that they may benefit from training to improve their detection ability and /or interpretation of vehicular gap times. (Author/publisher)
Samenvatting