Identify trigger factors for accidents in dense crowds

Determine the specific trigger factors that lead to accidents in dense pedestrian crowds and characterize how these factors delineate life-threatening situations from regular densely crowded conditions.

Background

The chapter emphasizes that dense crowds can lead to severe outcomes such as collective falls, chest compression, and asphyxia, yet most dense-crowd events do not result in accidents. This disparity highlights the need to understand what precipitates critical incidents.

Despite decades of modeling and observational work, the authors note that the precise factors triggering dangerous events in dense crowds are not clearly established, complicating risk assessment and the identification of thresholds between routine dense crowding and hazardous conditions.