Abstract. This paper presents the research and development of a volumetric 3D visibility analysis application to assess public space in regards to safety and security. While most of the academic literature on space visibility concentrates on developing viewsheds from a specific viewpoint, this work integrates dynamic scenarios and real-time calculation of space visibility. Voxel-based spatial representation is utilised as a base for the 3D visibility analysis. Different space configurations are tested illustrating the robustness and usefulness of the developed application. In order to measure and evaluate different safety zones, an innovative approach is tested according to which the number of times each voxel is observed is recorded and further classified into different zones. In this way, an accurate calculation of the observed space can be performed understanding which part of an area of interest is less or more observed. The research has shown great potential for first responders, researchers, architects and safety experts. The developed application can be used as a simulation tool to assess the safety of different urban environments and identify potentially vulnerable locations.