Our work aims to check – combining sociology (surveys) and computer science (simulations and machine learning) techniques – how mobility choices affect daily travel to school in the context of a 15-minute city and physical activity (PA). The simulations based on survey data collected among parents of primary school pupils enable estimating how the 15-minute city concept as a psychical activity trigger is already present in the citizens’ behaviour. Travels from the home to the children’s school are routed using a spatial data analysis platform supported with OpenStreetMap data and public transport timetables. The results allow us to compare travel parameters according to the transportation used. Although the three examined schools are mainly localised near the home address, we have shown that less than 50% of cases fulfil the 15-minute city restrictions. We have also shown the benefits of public transport on PA and analysed distance and other factors limiting PA.