Are Post-Soviet Cities 15-Minute Cities? Differences in Pedestrian Accessibility of Basic Urban Services by Residential Development Morphotypes in Krasnodar, Saratov, and Naberezhnye Chelny

The 15-minute city concept suggests redesigning cities and urban areas in such a way that every resident could reach basic necessities and services, including education, medicine, shopping, leisure, etc., within a 15-minute walk or bicycle ride. The underlying goal of the concept is to improve urban environment, to reduce pressure on transportation systems, and to make cities more resilient to events like the COVID-19 pandemic, when many cities imposed restrictions on cars and public transport. In this paper, we use the 15‑minute city concept as an analytical framework for an accessibility index describing the quality of the urban environment in contemporary Russian cities. The study is based on the assumption that the morphologically heterogeneous environment of the post-Soviet cities creates different conditions for the location of facilities that provide residents with basic necessities and services; as a consequence, the accessibility of these facilities varies greatly within cities. Three large and morphologically different post-Soviet cities, Krasnodar, Saratov, and Naberezhnye Chelny, were chosen as the study cases. The investigation draws on publicly available data as well as data from 2GIS on social, commercial, and transportation infrastructure. From our results, the highest accessibility of the facilities is observed in the historical city centers, which concentrate the facilities that provide unique and city-wide services. The Soviet microdistricts show the higher accessibility values compared to modern high-rise multi-unit residential buildings, while the lowest accessibility is observed in the low-rise neighborhoods: the average walking time to the basic services and facilities here is three times longer than in the historical centers, and twice as long as in the Soviet microdistricts. Among the three cities studied, Naberezhnye Chelny is the closest to the 15-minute city model. For daily demand facilities, the accessibility varies little between the cities, with 86.0 to 92.2% of residents living within 15-minute walking distance. The strongest differences between cities and urban areas of different morphological types in the accessibility of the facilities are observed only when including in the index rare facilities that provide unique and city-wide services, such as hospitals, theaters, universities, etc. Their accessibility can be improved, for example, by developing public transport systems or creating sub-centers of urban activity in high-density residential areas.