Emergent regularity of walking patterns: evidence from Swiss cities

Abstract

Human travel behaviour is characterised by high temporal and spatial regularity, as demonstrated by the Exploration and Preferential Return (EPR) mechanism, whereby individuals alternate between exploring new locations and preferentially returning to previously visited places. Yet, existing evidence is based on aggregated mobility data that cannot distinguish short trips or separate active mobility (i.e., walking and biking) from other mobility modes. This limits our ability to assess the benefits of walking activities and proximity-based policies such as the 15-minute city. Here, we analyse the spatial distribution and duration of walking habits of 1,318 participants, tracked during a 4-week time use survey in major Swiss cities - which are very close to the 15-minute city model. We find that walking activity is highly concentrated around individuals' home and work locations. These two attractors create walking patterns that are fundamentally different from other transport modes, which are instead used for longer trips and to connect home-workplace. We then introduce a dual-center EPR model, with empirically derived parameters, to simulate the decaying probability of walking away from the centers. Combining empirical data and the EPR framework, we find that groups with higher walking times show a stronger tendency to take long-distance walks and explore more destinations. In general, walking behavior reflects both individual circumstances and residential context: walking durations are shorter among people without a public transport pass, car owners, and residents of low-density rural areas. These findings provide a basis for more targeted assessments of walkability and active-mobility-oriented urban design.