A Scalable Approach to Equitable Facility Location

Abstract: Achieving equitable access to essential services, such as healthcare, food, and education, is a critical goal in urban planning and public policy. However, existing facility location models primarily focus on optimizing average accessibility, often neglecting equity concerns, particularly for disadvantaged populations. This paper proposes a novel, scalable framework for equitable facility location, introducing a linearized proxy for the Kolm-Pollak Equally-Distributed Equivalent (EDE) metric to balance efficiency and fairness. Extensive computational experiments demonstrate that, unlike other facility location models that incorporate measures of equity, our approach scales to extremely large problem instances. Optimal solutions represent significant improvements for the worst-off residents in terms of distance to an open amenity, while also attaining a near-optimal average experience for all users. Two real-world case studies -- supermarket access and polling location access -- illustrate the practical applicability of the framework. Furthermore, the model is extended to handle real-world considerations such as capacity constraints, split demand assignments, and location-specific penalties. By bridging the gap between equity theory and practical optimization, this work offers a robust and versatile tool for researchers and practitioners in urban planning, transportation, and public policy.