Quantitative Systemic Approach to Identify Barriers to Peer-to-Peer Car-Sharing

Peer-to-peer car-sharing (P2PCS) is a mobility solution in which vehicle owners make their cars available through digital platforms that mediate booking, access, and fleet management. Although P2PCS can offer theoretical advantages in terms of resource efficiency and reduction in private ownership, its market scaling is critically dependent on users’ perceived value. In this context, the present study investigates systemic determinants of scalability in the P2PCS market using a Mixed-Methods Research (MMR) approach, combining a literature review, expert survey, focus-group interviews, Interpretive Structural Modeling (ISM), and cross-impact matrix analysis (MICMAC). This combined approach allows for the identification of barriers and their position within a hierarchical structure of interrelationships, influence, and dependence. The most influential determinants are emotional attachment to private car ownership, legal and regulatory uncertainty, stakeholder misalignment, infrastructure constraints, and ambiguous insurance coverage. By analyzing the hierarchical interrelationships between these determinants and their respective driving and dependence powers, experts in a focus group suggested a set of targeted measures to address the P2PCS system of barriers. Proposed measures include regulatory sandboxes to safely test innovative business models, modular and usage-based insurance products, the promotion of public–private partnerships for shared mobility infrastructure, the advancement of digital interoperability across smart mobility services, and communication campaigns to foster sustainable travel behaviors. Collectively, the findings provide a decision-support framework for policymakers, P2P platform operators, and municipalities, illustrating how the Mixed-Methods Research approach can deepen understanding of the socio-technical interdependencies that shape the effectiveness and scalability of emerging mobility solutions such as peer-to-peer car-sharing.