Evaluating the Impacts of the Built Environment on Active Travel: The Role of Alternative Modes

Promoting active travel is a common practice in transport planning and public health. Despite rich literature that has explored the impacts of the built environment on active travel, the choice aspect of travel behaviors is still not explicitly considered. In this study, we address this issue by estimating count models that relate the built environment factors with active travel in two cases, with and without the inclusion of variables representing alternative modes. By this, the role of alternative modes, which reflect the choice aspect of travel behaviors, can be revealed through examining the changes in the estimated parameters caused by the inclusion of these variables. Data from an online survey conducted as part of the multiple-year national project Smart Mobility Challenge in Japan in 2021 were used for estimations. The result showed significant effects of the built environment factors on walking and cycling numbers. More important, these effects varied noticeably over whether variables of alternative modes are included. Safety Concerns was the only factor with its effects being unaffected by the presence of alternative modes. The effect patterns of the remaining factors changed significantly with the presence of alternative modes, particularly in models for cycling numbers. Services Nearby was the only factor that had strong and significant effects on both walking and cycling numbers. The presence of alternative modes also resulted in the elimination of behaviorally counterintuitive parameters. Overall, the study provided supportive evidence for the mediating role of alternative modes in the associations between the built environment factors and active travel. We strongly recommend considering these variables, and the choice aspect in general, in studying the environmental correlates of active travel. Environmental measures aimed at attracting active travel may yield better results if focusing on non-car users.