Assessing the readiness for 15-minute cities: a literature review on performance metrics and implementation challenges worldwide

The 15-minute city (FMC) has recently emerged as a popular planning paradigm. While the concept builds upon well-stablished urban planning principles, such as density, mixed use, and proximity, its operationalisation in research and practice faces methodological and contextual challenges. This study conducts a systematic review of FMC performance metrics, analysing thirty-nine peer-reviewed articles analysing how assessment metrics have been defined and used to evaluate the alignment of a region with FMC principles across different geographical contexts. We categorise performance metrics into six broad groups: amenity-based, population-based, distance-based, gravity-based, behaviour-based, and weighted scores. The findings reveal significant methodological diversity, particularly in time thresholds, transport mode choices, and the selection of amenities. European and Asian studies tend to focus on the spatial distribution of amenities, while North American research emphasises behavioural analysis, highlighting the challenges posed by car dependency and urban sprawl. This review identifies key research gaps, including the limited attention given to digitalisation and equity concerns. Additionally, we highlight the need for standardised performance metrics to allow for comparability across studies. Given regional variations in urban form and behaviour, we argue that FMC policies should not adopt a one-size-fits-all approach but rather be tailored to local contexts. The findings from this research can be of interest to policymakers interested in understanding the regional challenges and methodological variations of FMC performance metrics.