Repositioning the 15-minute city concept in a multi-scale spatial reading: the contributions of the Fractalopolis methodology


  • Xavier Lehmann Université Gustave Eiffel, LVMT
  • Olivier Bonin Ecole des Ponts, Université Gustave Eiffel, LVMT
  • Pierre Frankhauser Université de Franche-Comté, ThéMA


Proximity-based accessibility, Urban system, Multi-scale approach, Active mobility




The 15-minutes city concept highlights the importance of putting proximity back at the heart of planning approaches, in order to focus accessibility to the amenities needed for daily life around short distances and encourage walking (Büttner et al. 2022). This concept, which has gained considerable momentum among politicians and academics, has important elements that need to be introduced or reaffirmed among operational urban planners. As well as reflecting important issues of spatial justice, the concept of the x-minute territory requires an exhaustive reflection on the relationship that individuals have with the satisfaction of their needs and the mobilities this generates. In the majority of methods used to formalize the concept, a potential for proximity accessibility from each location is calculated, based on a certain number of amenities and on distances deemed satisfactory to favor active modes over motorized modes. These choices raise a number of questions that need to be answered in order to enhance the adaptability of the methods and the interpretation of the results. One of the main criticisms that the concept has raised is its assumed "monoscale" anchoring, around a distance threshold representative of proximity (Lebrun, 2023). While this choice can be explained by a preference for strengthening active modes of transport, it is nevertheless restricted to certain types of equipment concerned by this specific location. We believe, however, that this concept provides a relevant analytical key for reorienting planning policies towards greater spatial proximity, if it is placed in dialogue with all the scales of interaction between the individual and the territory in which he or she lives.

With this in mind, we will present a multi-scale accessibility analysis methodology based on the use of Fractalopolis software (Frankhauser, 2021). The application of this tool is based on a diversified protocol, combining an analysis of urban planning documents and the use of geospatial data. Based on a detailed understanding of the urban framework of the territory in question, a hierarchical spatial system is constructed, respecting the complementarity of polarities between geographical scales. On the basis of this spatial system, adapted to the morphological realities of the application area, a set of accessibility rules is applied. These rules involve several indicators usually found in tools for measuring the 15-minutes city: a selection of points of interest to which inhabitants must have access, and proximity distance thresholds associated with them. In Fractalopolis, the shops and services selected for analysis are also categorized according to frequency of use and percentage of users, enabling results to be refined according to the principles of needs theory and residents' consumption practices. Taking population distribution into account in the software's accessibility calculations also paves the way for the development of prospective scenarios to simulate the evolution of this repair according to observable or desired trends.

Thus, the aim of this presentation is to place the 15-minutes city concept at the heart of a multi-scale approach to accessibility based on proximity, by refining the choice of types of conveniences and distance thresholds according to residents' practices and the morphological realities of territories, at all spatial scales. To illustrate these principles, several examples of application territories will be presented, illustrating a diversity of geographical and socio-spatial contexts (Ile-de-France region, Rabat conurbation in Morocco, etc.). Finally, the development of the Fractalopolis software is part of a wider project to provide planning stakeholders with a robust and relevant decision-making tool for the revision of their urban planning documents and the development of projects.


Büttner, B., Seisenberger, S., Baquero Larriva, M., Gante, A., Ramírez, A., & Haxhija, S. (2022) Urban Mobility Next 9 ±15-Minute City : Human-centred planning in action Mobility for more liveable urban spaces. EIT Urban Mobility, Munich, November 2022.

Frankhauser, P. (2021) Fractalopolis : a fractal concept for the sustainable development of metropolitean areas. Complex Systems, Smart Territories and Mobility, Springer International Publishing, pp.15-50.

Lebrun, N. (2023) Réinterroger la centralité marchande. Pôles, territoires, discontinuités et réseaux au service de la centralité. Géographie. HDR. Université Paris 8 – Vincennes-Saint-Denis, ⟨tel-03961158⟩