Modeling car dependency and policies towards sustainable mobility: A system dynamics approach

Abstract

Despite decades of research on urban transportation, few researchers apply a holistic understanding of the urban transport mechanism. To address this gap, in this paper we employed a two-stage modeling approach using a system dynamics method and theory of path dependence. First, an exploratory model presents the structure, including feedback loops and underlying mechanisms of the evolution of car dependency. The model explores loop dominance, and implicit goals determine whether it is a car-dependent or transit-oriented and active modes-based transport system. Car dependence arises from the dominance of road-based feedback loops for commuters to achieve their transportation goals. Second, a revised policy structure reveals that shifting the loop dominance towards transit-oriented and active modes-based transportation system is possible when commuters achieve their goals through transit and active infrastructure-based feedback loops. The scale and timing of policy leverages determine the thresholds for the loop dominance shift.