A Conceptual Sustainability Assessment Framework for Urban Micromobility Systems

Urban micromobility systems are increasingly deployed to support sustainable transportation goals; however, their overall sustainability performance remains inconsistently assessed across environmental, social, economic, and operational dimensions. This study proposes a conceptual framework for evaluating the sustainability of urban micromobility systems, with a particular focus on e-scooters. It clarifies and restructures fragmented indicators into distinct, non-overlapping sustainability dimensions. The framework is structured around five impact areas: Environment, Economy, Users, Transport Performance, and Safety, complemented by two enabling components, namely the legal framework and business model, which are conceptualized as preconditions for system feasibility rather than performance dimensions. Building on existing sustainability assessment literature, the framework consolidates established indicators while introducing micromobility-adapted and context-specific indicators, such as service availability and operational characteristics, to better capture the distinctive features of shared micromobility systems. The resulting framework provides a structured and flexible tool for researchers, planners, and policymakers, emphasizing that micromobility sustainability depends not only on measured impacts, but also on governance, operational design, and local implementation conditions.