Crowd density - the number of people per square metre - for standing and moving crowds, is important in understanding the efficiency of filling spaces at events and/or crowd flow in the complex and built environment. The diagrams below show the various levels of service (density) and at the bottom of this page is a look-up table for flow rates. At the crowd density increases then flow rate will increase UNTIL the density reaches the critical limit (Cd). At that point (density limit) the individuals cannot take whole paces and the crowd flow begins to decrease as a consequence.
These are examples from the Crowd Dynamics Workshop. For a full set of slides, notes, background, teaching aids and additional materials see www.crowddynamics.org.
1 Person per Square Metre 1.5 People per Square Metre
2 People per Square Metre 2.5 People per Square Metre
3 People per Square Metre 3.5 People per Square Metre
4 People per Square Metre 4.5 People per Square Metre
5 People Per Square Metre
1 Person per Square Metre 1.5 People per Square Metre
2 People per Square Metre 2.5 People per Square Metre
We observe Cd around 2-3 people per square metre. Capacity density (k) is defined as a specific function for a specific environment. The graph below illustrated this - each environment has a different capacity density.
In general we calculate crowd flow at 82 people per metre per minute maximum - this is at the 2-3 people per square metre density limits. Above that critical density the crowd flow is both unstable and congested.
