Nonlinear built environment impacts on travel behavior: A systematic review and meta-analysis

Built environment improvements are widely recognized as essential for reducing automobile dependence and promoting active travel and transit use. A growing body of empirical evidence indicates that the built environment exerts nonlinear impacts on travel behavior. This study reviews existing research focused on these nonlinear associations. Utilizing a novel data extraction and aggregation process, we synthesize the nonlinear relationships between built environment attributes and three types of travel behavior: driving, transit, and active travel. Forty-eight studies using non- or semi-parametric models are identified, primarily conducted in China and the United States. The aggregated relationships suggest that built environment elements exhibit moderate effects on travel behavior and show nonlinear associations. We further identify common thresholds at which built environment factors simultaneously affect multiple travel behaviors. Finally, we highlight key directions for future research, including establishing causal relationships, examining spatial and contextual heterogeneity, and uncovering underlying mechanisms.