Cities across the global are looking for structural systemic solutions to mobility related problems such as congestion, pollution, and lack of (public) space. Electrification seems to accelerate and address (local) environmental problems, but not necessarily contributes to just mobility by opening up public space, creating broader access to mobility and supporting health. In this paper we describe an experimental transition governance process in the city of Rotterdam, the Netherlands, in the context of the local climate agreement. It used transition governance to explore how the social, cultural, institutional and technological changes needed to achieve a just and sustainable mobility future could be accelerated. The politically supported but informal governance process mobilized public-private-civil networks of actors in the context of the local climate agreement to co-create a transition strategy based on zero-emissions, social and shared mobility in 2030, aiming for all vehicles left to be shared and free from tailpipe emissions. It accelerated a number of debates, actions and changes in the city and pushed local policies to further prioritize walking, cycling, sharing and public transport. Its ambitions have helped shape current formal urban spatial and mobility policies and institutional experimentation in the city, accelerated during the COVID pandemic.