Setting boundaries and thresholds in transportation research and policy: Between principles of sufficientarianism and limitarianism

This paper rethinks transport research and practice by integrating two distributive justice principles: sufficientarianism and limitarianism. While sufficiency has shaped debates on minimum accessibility, basic needs and mobility rights, the notion of upper thresholds or limits, central to limitarian thinking, remains underexplored. Drawing on transport, environmental, and political philosophy scholarship, we propose a normative mobility-accessibility-wellbeing corridor that guarantees accessibility to fulfill basic needs while curbing resource-intensive travel that exacerbates environmental degradation and undermines collective wellbeing. Combining features of a narrative and critical review, we examine cross-disciplinary frameworks on boundaries, critically discuss the main challenges when defining and navigating trade-offs between lower and upper thresholds in transportation, and illustrate how these principles are associated with established and emerging transport policies. We conclude with a discussion of further conceptual, empirical, and policy-oriented research directions opened up by this approach.