Exploring Perceived Vulnerability of Pedestrians: Insights from a Forced-Choice Experiment

TL;DR

This study investigates how pedestrians perceive the vulnerability of others in crowds, revealing that wheelchair users are perceived as most vulnerable, which could influence social spacing and safety considerations.

Contribution

It introduces a novel forced-choice experiment to quantify perceived vulnerability of pedestrians based on visual stimuli, highlighting differences due to mobility aids and carried items.

Findings

Wheelchair users perceived as most vulnerable.

Persons without items perceived as least vulnerable.

Carrying two suitcases yields intermediate vulnerability perception.

Abstract

Individual differences in mobility (e.g., due to wheelchair use) during crowd movement are not well understood. Perceived vulnerability of neighbors in a crowd could affect, for example, how much space is given to them by others. To explore how pedestrians perceive people moving in front of them, in particular, how vulnerable they believe them to be, we asked \SI{51}{} participants to complete a Two-Alternatives-Forced Choice task (2AFC) in an internet browser. Participants were shown pairs of images, each showing a person, and then asked to select the person who appeared more vulnerable to them. For example, participants would choose between a male person in a wheelchair and a female person carrying a suitcase. In total 16 different stimuli (male vs female; no item/device, 1 suitcase, 2 suitcases, small backpack, large backpack, stroller, cane, and wheelchair), yielding n(n-1)/2 = 120 potential pairwise comparisons per participant. Results showed that wheelchair users appeared the most vulnerable and persons without any items/devices the least vulnerable. Persons carrying two suitcases were in the middle. These results informed the design of a main behavioral study (not reported here).