Abstract
Purpose:
The aim of this study was to determine whether the street-crossing decisions of young and older normally-sighted subjects was affected by the complexity of the street design.
Methods:
Street-crossing decisions and crossing times in 51 young and 49 older subjects with normal vision were measured along a one-way street, a two-way street and a roundabout. Using their habitual vision and hearing, subjects observed approaching traffic for a given period of time. At the end of the observation period, subjects were required to make a crossing decision of whether or not they thought it was safe to cross the street. Subjects’ crossing decisions were then objectively classified as being “safe” when the measured gap time was longer than the subject’s street-crossing time. The converse was true for objectively classifying crossing decisions as being “unsafe”. The percentage of correct crossing decisions (ie. subjects correctly identifying “safe” and “unsafe” trials) and the percentage of unsafe crossing decisions (ie. subjects reporting it was safe to cross for objectively unsafe trials) was determined for each subject at each type of street. A linear mixed model with repeated measures for subject was used to determine if the proportion of correct and unsafe decisions changed as a function of subject group (age) and type of street.
Results:
We found that the older normally-sighted subjects performed as well as the young subjects at all three types of streets (p>0.06). Performance did vary however as a function of the type of street (p<0.001). No significant difference in the percent correct (p=0.76) and unsafe (p=0.51) decisions were found between the one-way street and roundabout. Subjects made a higher number of correct decisions at the two-way street than at either the one-way street (p<0.001) or roundabout (p<0.001). Similarly, subjects made a higher number of unsafe decisions at the two-way street than at either the one-way street (p<0.001) or roundabout (p<0.001).
Conclusions:
Our data suggests that the design of the street as opposed to age affects a pedestrian’s ability to make street-crossing decisions. In general, younger and older normally-sighted pedestrians tend to adopt an aggressive crossing strategy at the more complex two-way street than at the one-way street or roundabout. There appears to be a similar level of complexity involved when making crossing decisions at the one-way street and roundabout.