Building a 15-Minute City: A Methodological Approach for Assessing the Socio-economic and Environmental Effects of Locating Amenities in Low-Density Settlement Contexts

For the past six decades, the occupation of built-up land in Europe has resulted in the development of low-density settlements marked by a strong level of unsustainability due, among others, to the consumption of limited resources and dependence on cars, leading to pollution and economic inefficiency of all system. The 15-minute City model offers a valid alternative to 20th-century urban planning that relied heavily on cars as citizens’ primary mode of transportation. Inevitably, the time spent in the car to reach the primary amenities generates adverse effects on the psychological well-being of individuals and the quality of life. A city designed according to the 15-minute city theory will have amenities located in a well-distributed and demand-dependent manner. To highlight the positive aspects of this city model, this research analyzed the costs resulting from the effects of urban transformation in contexts with low settlement density and a high rate of urban dispersion (recognized as the urban sprinkling phenomenon) where the 15-minute city model has not been pursued in the urban planning process. Therefore, a case study on Potenza municipality (Basilicata Region, South Italy) was compared with similar analyses developed on Ferrara municipality located in the Emilia-Romagna Region (North Italy). From the analysis of data on population, commuting, travel time, and localization of amenities, the results show that although the two contexts are different in terms of population, morphology, and territorial surface, the city of Potenza has a much less economically and environmentally sustainable urban spatial configuration compared with Ferrara city.