Beyond proximity: How psychological factors drive active travel in 15-minute cities – A SEM analysis

Proximity-based planning models, particularly the 15-minute city, are increasingly promoted as strategies to encourage active transport and reduce car dependence. However, improvements in the built environment alone may not lead to sustainable travel behavior without considering underlying psychological drivers. This study applies the Theory of Planned Behavior (TPB) extended with habit to examine how attitudes, perceived behavioral control (i.e., individuals’ perceived ability to walk or cycle), subjective norms, intention, and habit shape sustainable travel behavior within a proximity-based urban context. The analysis is based on a survey of 201 residents across two neighborhoods in Qazvin, Iran, which differ in levels of local accessibility and perceived proximity to services. Using Structural Equation Modeling, the results show that perceived behavioral control (β = 0.213) and habit (β = 0.402) exert the strongest effects on intention to use active and sustainable transport modes, while attitude (β = 0.187) also plays a significant role. The neighborhood with higher perceived accessibility demonstrates stronger behavioral readiness for active travel, highlighting the interaction between spatial conditions and psychological factors. The findings indicate that proximity planning is most effective when physical accessibility is complemented by supportive behavioral conditions, particularly in car-dependent urban contexts in the Global South. This study contributes empirical evidence and a transferable analytical framework for integrating psychological dimensions into the implementation of 15-minute city strategies.