© 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0)Public spaces, being inevitable components of cities, are evolving spaces that transform, expand or shrink. Ideally, they should be publicly-owned and controlled, equally accessible to all, and function in the public interest. As the main actor of public spaces, this research aims to reveal the roles of pedestrians’ behaviour and mobility in making public space. It proposes a model to assess the mobility capacity and pedestrian behaviours regarding pre-determined inner and outer factors and indicators. The coastal park, which was developed through the coastal reclamation in Mersin that is a Mediterranean city in Turkey, is selected as the case study. The findings of the spatial morphological analyses, direct observations and users survey show that, while some areas in Mersin coastal park are used very effectively by pedestrians, some areas are not used sufficiently and remain idle. Based on the proposed model, this research reveals how pedestrian behaviour and movement affect the public space-making in the coastal park, and discusses the findings of the research in relation to the inner and outer factors of making public spaces. It ultimately seeks to show the critical role of the pedestrians’ behaviours and their mobility capacities in creating lively and high-quality public spaces.