The proposed project focuses on the policy of abolishing fares in public transport (PT) systems, otherwise known as fare-free public transport (FFPT). Although FFPT has become an established practice, discussed and implemented by policy-makers across Europe, it remains largely controversial and under-researched. The main objective of the project is therefore to understand both transport-related (economic, operational) and urban (social, spatial and political) aspects of FFPT. The project builds on three research strategies, each involving both qualitative and quantitative methods. First, to unpack economic and operational dimension of FFPT (i.e. to understand how much fare abolition costs, and how it works), a global survey of all its detected cases will be conducted, providing the most comprehensive analysis of the policy to date. Second, the particular cases of Dunkirk and Luxembourg will be studied. Multisource user surveys and in-depth interviews will be conducted to investigate how fare abolition affects travel behaviour, lifestyle and well-being across diverse socio-economic groups. Local stakeholder, political bodies, electoral programmes and media will be analysed to unpack the spatial and political impact of FFPT, across institutions and administrative boundaries. Third, together with expert focus groups, the project team will build on insights from Dunkirk and Luxembourg to project and analyse scenarios for potential fare abolition in Brussels.