Crowd Flow

Considerations

Flow Rates (Rates of Passage)

The rates are typically expressed as the number

of people for each metre of width who can pass

a given point per minute (people per metre width

per minute).

Such calculations will be relevant in respect of:

‒ Calculation of ingress capacity/time

‒ Circulation of persons around the event/venue

This will be particularly relevant in respect of

egress and evacuation capacity calculations and

times

What factors do you consider relevant in

determining appropriate flow rates for your events?

Type of event

Dynamics of crowd

Nature of surface, slopes/steps, obstructions

Profile of audience (include child/mobility considerations)

Destination/objective

Crowd density

Bags and equipment

Safety management

Reaction times

Distance to travel

Fatigue

Historic behaviour

Uneven distribution

Lack of familiarity

Lighting

Traffic

Weather

NORMAL OR EMERGENCY This is not intended to be an exhaustive list

Three major influences

density of crowd (numbers/square metre)

speed of movement

number & widths of exits (including consideration

of pinchpoints outside of the venue/site)

What guidance may be applicable to rates of passage?

Guide to Safety at Sports Grounds

The entry capacity is the number of people who can pass through all the turnstiles or entry points serving either the whole or one section, within the period of one hour. For the purpose of calculating the entry capacity, the upper limit is set at 660 persons per turnstile (or other entry point) per hour

The rates are expressed as the number of people for each metre of width who can pass a given point per minute (people per metre width per minute).

On all stairways and on all routes within seated accommodation (including gangways, concourses and ramps) the amended upper limit is given as 66 spectators per metre width per minute.

On all other routes (including within standing accommodation) the amended upper limit is stated as 82 spectators per metre width per minute.

These values should not be used to calculate safe egress rates – they are upper limits only. At best they give a rough guide for assessing evacuation but there are hidden implications that need discussion.

What guidance may be applicable to rates of passage?

Fire Safety Risk Assessment (Open Air Events and Venues)

The capacity of an escape route is determined by the rate by which people pass along the route during each minute of the defined escape time. The following are the suggested rates of passage for open air parts of venues:

On all routes within seated accommodation (including gangways and ramps) and stairways – 73 persons per metre per minute

On all routes in other parts of the event or venue (including within standing accommodation) – 109 people/metre/minute

Speed of movement

This tells us that we may

typically expect that

when a moving crowd

reaches a density of 4

persons per square

metre speed of

movement slows

dramatically.

In confined space this

can be a significant

safety concern

Remember 3 Fs

Flow

Fill

Fail

What do we mean by egress time?

Egress - time taken, under normal conditions, to

leave viewing area to enter free flowing exit system

- normally 8 minutes.

Contrary to some misunderstanding this does not

always imply emptying a sports ground.

This is typically 8 minutes for sports grounds

Telstra Dome - Melbourne

Telstra Dome - Melbourne

Station

Telstra Dome - Melbourne

Background

Up to 55,000 spectators

Raised external

concourses

Approx 80% wish to use

rail/tram systems

Aerial walkway is only

option to access

rail/tram station

Steps at far end to

access station

Swedbank Arena Stockholm

Swedbank Arena Stockholm

Shopping Centre

Robbie Williams, Knebworth (2003)

The ‘Bridge of Despair’

3 consecutive nights

125,000 per night

40m of arena exit width leading to 15m gap – classic pinch point.

Not enough lighting

Illegal traders blocking footpaths

‘Mass’ egress from arena (‘push’)

Majority of audience departing to car parks via this route

How can Design, Information,

Management help on next two nights?

So how can it go wrong?

Background

Free electronic dance event at former

rail yard

Capacity of site around 250,000 though

many more expected (reports suggest

up to 2 million)

Access from East and West via tunnels

Ingress/egress agreed via one ramp,

although a second is available but

closed

Reports suggesting that venue was full

which caused ingress to be halted

Flow into tunnels continues increasing

density and some attempt to leave

Progressive collapse/crush results in 21

deaths and 500+ injured

24 July 2010

Love Parade, Duisburg,

Germany

So how can it go wrong?

Background

Last day of National Celebration

featuring traditional boat races

(420 boats)

Hundreds of thousands in

attendance (estimates suggest 2

million)

Tens of thousands on bridge

connecting to Diamond Island

where concert and exhibition

were being staged

Reports that bridge was

collapsing

Progressive crowd collapse

351+ dead, hundreds injured

23 November 2010

Water Festival, Phnom

Penh, Cambodia