Crowd behaviour, crowd dynamics and risk assessment
This domain tests how crowds actually behave and how to turn observation into a dynamic risk assessment. The exam rewards density, movement and exit analysis over stereotypes.
Crowd dynamics
Crowds are not a single mind. Casual crowds share space; cohesive crowds share purpose; expressive crowds share emotion; aggressive crowds can form quickly. Deindividuation, alcohol, heat, noise, poor information and perceived injustice raise risk. Density matters: sustained crowding above about four to five people per square metre restricts movement and breathing; crush risk rises where exits are narrow or blocked. Emergent norms mean bystanders can help or hinder. Panic is less common than freezing, queuing and counterflow.
Risk assessment
Use a structured process: identify hazards such as capacity, queues, alcohol, weather, stage design, egress and rival groups; estimate likelihood and impact; set controls; and reassess as conditions change. Dynamic assessment is continuous: scan, compare with baseline, act early. Controls include capacity limits, separate ingress and egress, barriers, visible stewarding, clear PA messages and contingency plans.
Worked example
At a concert the front barrier compresses. The controller notes density, distress and a blocked side exit. They stop new entry, open the side exit, use PA to move the crowd back, and call the event controller. Waiting for Police would miss the window.
Traps
Treating a crowd as "they're all drunk"; ignoring exit width; relying on one control; failing to record changes; assuming panic is the main danger.