The concept of the 15-minute City (15minC) is critical to fostering transitions to sustainable mobility. However, two main barriers exist to its implementation: first, the 15minC principles are hard to transfer to urban outskirts; second, the lack of attention to the social dimension in the design and implementation of mobility and accessibility solutions. COMMON_ACCESS aims to tackle these shortcomings with two dimensions of novelty. First, central to our approach is the idea of 'Commoning accessibility', which interprets the ability to access facilities and amenities as a common good and recognises it as a social and material resource co-produced by and belonging to all its citizens. Accordingly, the operationalisation of commoning accessibility needs to consider integrally: The provision of facilities and amenities The provision of sustainable options for personal mobility and logistics to access them The social organisation of such services and mobility/logistic options and the role of communities in sharing services, optimising resources and abilities The second novelty stems from the observation that commoning is accepted in academia but has yet to be applied in practice. COMMON_ACCESS seeks instead to focus on the translation into practice of commoning with the study of 'commoning accessibility experiments', such as community-shared (e-) bikes, (e-) cargo bikes; community micro-mobility and Active Travel Hubs; mobile community services; citizen-based dataset community tools to enhance digital connectivity; community parcel lockers; community-led cargo bike deliveries. The overall objective of COMMON_ACCESS is to explore the concept of Commoning accessibility and investigate its operationalisation in the urban periphery and suburban contexts, working closely with local planning authorities, businesses, and communities. This will be realised by fulfilling five key objectives: Objective 1 (O1): Develop and apply methodologies to map and explore (the variety of) accessibility conditions for transport and land use in urban outskirts and beyond. O1 will generate insights on location-specific constraints, opportunities, and conditions for the 15mC in the outskirts. Objective 2 (O2): Develop and apply methodologies to map accessibility interdependencies and identify existing CA experiments in urban outskirts and beyond. O2 will generate insights into the social organisation of mobility/logistic options focusing on the role of communities in sharing services and optimising resources and abilities within urban peripheries. Objective 3 (O3): Understand opportunities for activating and designing new CA (transition) experiments. O3 will provide methods and tools to enhance the potential of communities to implement CA experiments (including financial and governance aspects) Objective 4 (O4): Develop and apply methodologies for estimating the potential impacts of CA (transition) experiments on travel behaviour and access to opportunities Objective 5 (O5): Identifying policy enablers and constraints to commoning accessibility. O5 will generate insights into the key barriers and enablers for up-scaling successful street arrangements, district conditions, and alternative mobility options, including potential strategies for achieving this. By way of testbeds in outskirts neighborhoods of six different metropolitan areas - the Metropolitan area of Amsterdam (NL), the Province of Bergamo (IT), the Province of East-Flanders (BE), the Metropolitan area of Munich (GE), the Province of Pavia (IT) and Oxfordshire County Council (UK)- COMMON_ACCESS will collaborate and exchange knowledge with self-organised communities, SMEs, neighbourhoods, and local authorities in different contexts.