Theses and Dissertations Collection

Each year more than 140,000 adult pedestrians are struck by motor vehicles, resulting in heavy costs of both life and economy. Research has endeavored to investigate the etiology of pedestrian injury for decades. Recently a need has been identified – and begun to be addressed – for empirical work systematically examining the roles of vision and audition in various components in the pedestrian task. I designed and carried out two studies with the overall aim of investigating how safety is impacted if a pedestrian's perception is impaired on a sensory level rather than, for example, via distraction. Specifically, I conducted one study to examine the intrapersonal visual perceptual impairments introduced by alcohol intoxication, and another study to examine environmental sources of visual occlusion. The aforementioned intrapersonal and environmental sources of impairment were examined across two important components of the pedestrian task, time-to-contact estimations and gap selections. Secondary constructs known to be associated with one or both types of impairment were also be examined, including visuospatial performance, visual acuity, and contrast sensitivity. Alcohol intoxication negatively impacted time-to-contact judgment accuracy; no other significant effects of either intrapersonal or environment visual impairment emerged. I discuss my findings in terms of their implications for pedestrian safety research and for injury prevention efforts, and conclude with considerations for future research.