Enrico Ronchi - Department of Fire Safety Engineering, Lund University
During the COVID-19 pandemic, the research domain of crowd dynamics is under the spotlight, given the risk of virus transmission in confined and open spaces. All stakeholders dealing with crowds face new challenges concerning safety. The key challenge for fire safety engineers is the need to ensure crowd safety in case of concurrent threats, i.e. a fire and virus transmission. Evacuation modelling is a powerful tool to address this issue. In this context, the introduction of physical distancing recommendations and the risk perception concerning virus transmission can affect crowd movement and behaviour. This implies that evacuation models need to be calibrated and modified in light of the expected behavioural changes and the interactions between pedestrians and between pedestrians and their surroundings. Given the current limited knowledge on human behaviour and space usage during pandemics, this talk presents an overview of the possible uses and needed modifications of crowd evacuation models. This includes both proximity analysis as well as exposure assessment. A model for exposure assessment to retrofit crowd evacuation models, called EXPOSED, is also presented. EXPOSED allows the study of occupant exposure based on the analysis of pedestrian trajectories, considering different types of disease transmission mechanisms.