Cars and roads have helped create modern society. However, their use comes at a cost for cities and their residents, in particular with respect to liveability. To improve liveability, cities are implementing a wide range of measures. This paper addresses the challenges cities face in reducing urban car dependency and provides lessons from their experiences. Major research gaps exist around governance questions regarding real-world policy development to aid in the transition towards sustainable mobility.

Case studies in cities with comparable population sizes and experience in car-reducing measures, namely Copenhagen, Barcelona, Bremen, and Milan, provide new insights for policymaking, all to understand the context in which a policy can flourish and help policymakers make them more successful. These insights lead to a framework of success factors and barriers based on theory and practice for other policy makers to use.

Eight different success factors have been identified to overcome the five barriers and successfully implement their policies. Six originate from the literature and were confirmed in the case studies. The two final success factors of ‘the inarguability of schools’ and ‘the undeniability of hard evidence’, emerged from the cases.

In the cases interviewees identified and prioritised the links between these factors and barriers, and how the success factors can reduce the barriers. This research adds to the literature of real-world policy examples and includes issues of governance that policymakers may run into. The novelty is in the framework of success factors and barriers, based on the experiences of Western European cities with a comparable population size. The framework can be used by both policymakers and researchers to design and compare car-reducing policies.@en