Geospatial analysis framework for evaluating urban design typologies in relation with the 15-minute city standards

Abstract

Today, the majority of the world’s population lives in cities and it is expected that urban population will continue to grow in the coming decades. The increase in urban population will negatively impact urban performance, measured by equal access to amenities, knowledge creation and economic growth, if cities cannot respond to pressures that arise from increased migration. While urban design principles can help solve these problems, many core concepts of city form are often too abstract to allow for quantification of critical key indicators, comparative benchmarking for best practices and rigorous implementation strategies to ensure success. Given the complexity of how people interact with a city, the critical question arises: How does a city’s shape influence its urban performance? In this paper, we intend to address this fundamental question. First, we propose a framework to create a series of urban form typologies, which describe generally, a city’s shape and size, as a unifying concept to describe a city's design underlying pattern. Second, we propose that the urban form typologies can be quantified through the framework, to establish a disciplined methodology to compare the shape and scale of one city to another. The methodology combines topological (street network) and morphological (building form) features of urban form as well as other metrics related to geographic scale, entropy and density. Third, we provide a unified method to evaluate urban performance in terms of urbanization efficiency, innovation metrics and distribution of amenities. Fourth, we apply this framework to study the relationship between city typology and urban performance in order to determine which city designs are best suited to meet the demands of population growth, resource management, and energy usage. We apply this methodology to data gathered on 24 cities worldwide and their internal 8,228 subdivisions. By grouping the subdivisions into 208 agglomerations based on common urban form features, it is possible to identify and characterize their internal tapestry of city form typologies and evaluate their respective urban performance KPIs. We show that city typologies have a distinct effect on urban performance, quantify this impact and provide comparisons between the different typologies. Finally, we apply this methodology to evaluate the ability for each city typology to achieve the standards set forth by the 15-minute city, a sustainable development proposition of a decentralized city composed of walkable neighborhoods that provide equal access to housing, education and amenities.