Embedding the Capabilities Approach in Transport Network Design: A Multi-Period Optimization Framework with Endogenous Feedback

Abstract

This paper operationalizes the Capabilities Approach (CA) to inform resource allocation decisions in a transport network modeling framework. While existing studies recognize the role of the CA in equity-oriented policies and investments, integrating the normative theory into tractable analytical models remains limited. We address this gap by formulating a multi-period mixed-integer nonlinear network design problem that explicitly captures the relationships between resources, conversion efficiency, capability formation, and well-being. Conversion factors are represented through individual-specific travel costs and cost thresholds, enabling heterogeneous transformation of resources into capabilities. The framework further incorporates dynamic feedback, where achieved well-being lowers travel cost thresholds, thereby expanding spatial reach and influencing future capability formation. We compare feedback-aware and feedback-agnostic decision-makers, demonstrating how accounting for endogenous feedback alters optimal investment strategies. Additionally, we identify a critical capability threshold that provides an analytical interpretation of sufficiency-based justice. Sensitivity analysis highlights how population heterogeneity shapes longterm equity outcomes.