Module 1 of 9
Foundations: how crowds move
Everything in crowd safety reduces to three quantities and one curve.
5 lessonsAbout 3.5 hours3 interactives
What this module covers
This module builds a physical feel for density first: what one, two, four and six people per square metre look and feel like, and why the danger in a crowd is not its size but how tightly it is packed and whether it can move. Then come speed and flow, the arithmetic that turns a corridor’s width into a number of people per minute.
The third lesson draws the curve that ties them together, the fundamental diagram. Its peak is the capacity of every corridor, gate and ramp you will meet in this course, and its far side, where adding people lowers the flow, is where crowds become dangerous. Fruin’s Levels of Service then give you a vocabulary for what each band of density feels like.
The module ends where flow meets a wall: a bottleneck. You will see why a queue grows when arrivals exceed capacity, why the density just upstream climbs towards a standstill, and how cumulative curves let you read queue length and delay straight off a chart.
Expect to calculate. Every number comes with its source, and the three interactives let you check each idea by hand before you rely on it.