Five people per square metre

In the classroom exercises we illustrate the density v flow relationship using a loop of string. The loop has an area of 1 square metre.

At densities lower than 1 person per square metre the crowd is free flowing and stable. As we increase the number of people per square metre (which is why we are using the string to maintain the density), people cannot take whole paces forward. Movement starts to become constrained and the flow rates drops as shown in the graph below.

Click on the links below for a video clip of: 

2 people per square metre

3 people per square metre

4 people per square metre

5 people per square metre (marching in time)

6 people per square metre

© G. Keith Still.  All rights reserved (worldwide). All images, videos, audio files and text are protected under international copyright law  You may not copy, modify or use any of the website content, in whole or in part, for any commercial or non-commercial purpose without permission.  Contact email