The outside edge of the doughnut: Sustainable mobility and accessibility inequalities in Dutch transport policy

Transport planning is increasingly expected to pursue Community Wellbeing (CWB) objectives—not only keeping the mobility system efficient, but also shaping how benefits and burdens (e.g., access to activities, safety risks, health impacts, and environmental quality) are distributed across groups. Yet practitioners lack workable diagnostics that translate normative debates on minimum sufficiency and upper limits into policy directions that can be used in day-to-day appraisal and package design. This paper extends the Capability Approach (CA)-based evaluative framework for CWB-oriented transport policy by operationalising a joint “floor-and-ceiling” logic: sufficiency thresholds to prevent accessibility deprivation (inner edge) and limitarian ceilings to prevent unacceptable collective harms from mobility behaviour (outer edge). For the inner edge, calculated potential accessibility is distinguished from perceived accessibility, showing how mismatches imply different intervention logics (e.g., infrastructure/land-use change versus affordability, information, skills, confidence, or adaptive expectations). For the outer edge, it distinguishes whether behaviour is normatively undesirable due to collective CWB impacts and whether people have a sufficient capability set to adjust, clarifying when policy should expand capabilities to comply versus rely on regulation, pricing, incentives, and enforcement. The integrated framework is illustrated through four Dutch cycling-related cases and a narrative method for bicycle investment appraisal, demonstrating how the approach helps practitioners identify the problem’s location (inner, outer, or both), specify target groups, articulate CA-based pathways (resources and conversion factors → capabilities → functionings → collective outcomes), and anticipate trade-offs—especially the risk that enforcing ceilings can create new shortfalls if alternatives are not enabled. While grounded in Dutch practice, the logic is intended to be transferable through context-specific thresholds and ceilings and invites further testing in more conflict-prone domains such as parking, congestion pricing, and low-emission zones.