Measuring the 15-Minute City in Barcelona. A geospatial three-method comparison

Abstract

All neighborhoods need to offer the activities and social infrastructure to meet essential needs: personal wellbeing, mental health, and social equity; a sense of place and belonging; participation and choice; and now more than ever, the ability to successfully adapt to external challenges. The ability to be mobile through active transport and be able to access friends, activities, government, and business is a requirement to achieve most such needs. In that context, the 15-minute city (FMC) concept appears especially useful at testing the resilience and adaptability of urban areas. Living in an FMC based on decentralized, mini-hubs where everything you need is within a 15-minute walk or bike ride can make the difference between effectively being able to adapt to a crisis or becoming at risk of transport disadvantage. Numerous cities around the world have expressed their interest to pursue FMC planning principles, but to do so, a consistent and reliable method to measure those spaces is needed. Although there has been a recent boom in theoretical reflections around the concept of FMC, not many studies have tried to systematize and apply the theoretical conceptualization of the FMC into practice using publicly available spatial information. The present analysis sets to compare three distinct methods on how to measure the FMC using the municipality of Barcelona as a study setting. The first method proposes dividing the area in a grid of 100×100m and uses OpenStreetMaps API to estimate walking distances expressed as minutes to a set of everyday destinations. The second method uses residential cadastral parcels and the location of services and potential destinations to calculate minimum acceptable travel times. Finally, the third method uses actual travel behavior to map the areas that concentrate a larger number of trips made by walking and in less than 15min. Using Barcelona as an example, this study reflects on the strengths and weaknesses of each method, as a tool to answer specific research questions that can help use the FMC to create more sustainable and fairer urban environments.