Classifying 15-minute Cities: A review of worldwide practices

Amongst the most popular alternatives to the current car-dominant planning model to have emerged in recent times is the 15-minute City (15mC). The 15mC prioritises the notion of local living. It seeks to address the pressing challenges of urban life by promoting lifestyles largely independent of motorised travel modes by focusing on active mobility and proximity to essential amenities. Despite the popularity of this concept, a knowledge gap exists regarding the diverse range of international practical definitions, strategies, instruments, and implementation experiences, as well as the requirements for, and challenges involved in, operationalising the 15mC and related concepts. Consequently, this paper seeks to conduct a comprehensive analysis of the implementation of 15-minute cities and associated practices worldwide by combining an extensive literature review of both academic and grey literature sources with an expert survey. This culminates in the creation of a classification typology for the 15mC, based on the diversity of contexts and practices found, and informed by the Diffusion of Innovations Theory (DOI). Almost one hundred cities were identified as either in the process of implementing or planning to implement the 15mC concept. A diverse assortment of associated practices was identified, ranging from supporting active mobility to repurposing car space for other uses, promoting mixed land use and densification, and encouraging citizen engagement, among others. However, most cities are in the initial stages of executing their 15mC strategies, with the majority of practices still in the planning phase. Although cities worldwide have shown considerable interest in the 15mC concept, many have yet to embark on adopting comprehensive strategies or measures aimed at achieving more radical change, notably in areas such as logistics and governance.