Addressing pedestrian perceived externalities influenced by motor vehicles: A perspective from curb space typologies

Pedestrian externalities are usually generated by motor vehicles on urban infrastructure. There is a part of such infrastructure, called curb space, that separates pedestrians from motor vehicles. The literature proposes four main curb space typologies regarding the right-of-way (i.e., no lateral separation, lateral separation with no vertical barriers, lateral separation with vertical barriers, and on-street parking). However, there is little research reporting on how pedestrians perceive the externalities, or on the effects of externalities considering the previously mentioned curb space typologies. The purpose of this study is to identify the influences of externalities on pedestrians from the latter's perspective and considers their interaction with the built environment. To do so, we collected 1014 pedestrian responses related to their relationship with motor vehicles on 30 different sidewalks and some objective information (e.g., sidewalk width) on those sidewalks. Using a structural equation model approach, we identified a latent variable related with the pedestrian perceived externalities, which was defined based on a multiple indicators and multiple causes model for each of the curb space typologies. It was found that socio-demographic characteristics have a greater influence on the perceived externalities on curb spaces with no vertical barriers. In contrast, for curb spaces with vertical barriers, it is the built environment and operational characteristics that have a greater influence. We also identified the built environment and operational attributes influencing the perceived externalities on each of the curb space typologies. This research provides the tools to propose public policies related to transportation infrastructure interventions to reduce pedestrian perceived externalities.