Ethically informed urban planning: measuring distributive spatial justice for neighbourhood accessibility

Studies in urban accessibility have advanced our understanding of social and spatial inequalities in the distribution of urban resources in cities worldwide. In response, prominent discourse is shifting to embed justice in urban planning. Ethical principles have historically been employed by philosophers to guide thinking about reshaping society towards more fair and just outcomes. In this work, we present the Mapping Accessibility for Ethically Informed Urban Planning (MAP) framework. Map operationalises three metrics of distributive spatial justice based on Equality, Utilitarianism and Rawls’ Egalitarian principles to compare the implications of choosing different values of justice to evaluate neighbourhood accessibility. We apply MAP to three diverse cities located in the Netherlands, Mexico and South Africa, modeling each city as an urban network model, integrating public transportation, land use, and street networks. Across the cases and ethical perspectives, we find that the implications of defining justice is mediated by a neighbourhood’s proximity to local mixed land use for shorter commuting times. Whereas for longer commutes, it is dependent on a neighbourhood’s access to the Central Business District of each region, through transportation infrastructure. The findings underscore the scale, contextual and value-reliant nature of distributive spatial justice. MAP offers a means to facilitate comparative analysis within urban planning processes, highlighting different ethical concerns for debate by stakeholders and citizens.