Effect of Social Groups on Crowd Dynamics: Empirical Findings and Numerical Simulations

In 2009 a joint research project titled EVA started. It finished in Mai 2012 and covered various research topics related to risk assessment, planning and organization of large scale events. This paper will focus on empirical data collection and analysis and its use for the calibration and validation of the microscopic evacuation and pedestrian dynamics model ASERI. The empirical data presented here was collected at various large festivals and similar events like public viewing or championship celebrations. The focus is on established average and peak population densities. Extensions introduced into the ASERI simulation software as part of the EVA project include effects of group formation and group movement. Social groups in size of up to 6 persons are frequently present during public events. Quite often such groups comprise the majority of visitors. Walking behaviour and crowd flow of social groups differs considerably from those of single pedestrians. A fundamental diagram of walking velocity versus density of people could be derived from the analysis of the empirical data showing a considerable reduction in walking speed with increasing group size. This empirical findings can be reproduced by numerical simulations with the ASERI model.