Watch Out! Or do we? A Review of Literature on Human Locomotion, Visual Gaze, and Expectation of Trip Hazards

Abstract

Pedestrian trip and fall events, a major source of accidental injury and death, are often the result of a vertical perturbation that goes undetected by a pedestrian. Inattention is frequently blamed as the underlying root cause of the fall. However, research suggests that a pedestrian’s visual gaze is typically focused out towards the horizon and not towards the ground in the immediate vicinity of their feet, leaving them with poor visual acuity to detect subtle details on the walking surface. To the extent a vertical perturbation is unexpected, the likelihood of a trip event is increased. Relevant research on gait cycles, toe clearance, visual gaze, and expectation is examined to determine why pedestrians may fail to detect walkway hazards that are physically possible to see. Synthesis and future research are also discussed.

Case Study: An Analysis of a Sidewalk Trip and Fall after Repair Utilizing Photograph Scaling

“…This expectation of walkways could be influenced by pedestrians’ numerous successful interactions with walkway surfaces that do not result in a fall. Pedestrians traversing in a familiar walking surface where there have been numerous successful walking interactions may have a lower risk associated with the walkway surface and may be “less vigilant in the searching for hazards on the walkway in which they are interacting with (Dixon, and Nathan-Roberts, 2017, p. 1255, as cited in Ayres, Wood, Schmidt, & McCarthy, 1998). Though Mrs. Z was generally familiar with the incident sidewalk, she had never fallen or stumbled before near the incident area.…”

“…Details and objects that fall outside of a pedestrian’s field of view are “unlikely to be noticed and attended to unless they are made conspicuous by using properties such as blinking, motion, flickering, or high contrast in order to cause a shift in the pedestrian’s visual gaze” (Dixon, and Nathan-Roberts, 2017, p 1254). Most likely, Mrs. Z’s visual attention likely focused ahead on her vehicle and others in the parking lot rather than hazards located near her feet.…”