Table Of ContentPublic Safety S Introduction to
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“Really excellent work. It does a good job of taking a very sophisticated topic and l
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making it accessible for an educated reader.”
—Tracy Pearl, Florida International University, Miami Crowd Science
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“Every crowd management professional should read this.” n
—Andrew McQuillan, Director, Select Security, Belfast
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r G. Keith Still
“Keith Still’s work has focussed the minds of many people in realising just how
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easy it can be for disaster to occur and equally how simple the solutions often are.”
—Eric Stuart, Former Metropolitan Police Event Planner, UK d
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“The crowd science workshops are second to none and a real must for any crowd
safety professional.” c
—Andy Hollinson, Crowd Safety Training Project Manager, eResponse
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Recruitment & Training
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A well-grounded and practical guide, Introduction to Crowd Science highlights
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the underlying causes of crowd disasters and mass fatalities—giving the reader a
unique insight into crowd-related accidents. This book presents a clearer under-
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standing of crowd risks and provides the reader with a range of simple modelling
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techniques to plan and manage places of public assembly, leading to clear improve-
ments in crowd safety.
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It is written for students and professionals in a number of areas such as event
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organisation and management and the police and emergency services. It is focused o
on principles independent of any particular software and heavily illustrated with
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examples from practice, both good and bad.
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Keith Still has over 25 years of experience in crowd risk analysis and crowd safety.
He has worked as a consultant for major events, a trainer, an expert witness, and also
lectures around the world on crowd safety. Projects include the crowd management S
planning for the UK Royal Wedding (2011), Olympic Park (Sydney 2000 and
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London 2012), the Jamarat Bridge and the Holy Mosque (Saudi Arabia 2000-2012),
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and the Manchester City Etihad Stadium development (2014). e
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A SPON PRESS BOOK
K16858 cvr mech.indd 1 5/13/14 8:49 AM
Introduction to
Crowd Science
Introduction to
Crowd Science
G. Keith Still
A SPON PRESS BOOK
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
© 2014 by Taylor & Francis Group, LLC
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Version Date: 20140521
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Contents
Introduction xv
Preface xvii
Acknowledgements xix
Author xxi
1 Introduction 1
Why do we need this? 1
Are simulations the answer? 2
What we know 3
Uses of a crowd simulation 4
Site mapping 4
Workshops 5
Teaching and training 5
Crowd modelling 6
Crowd safety projects 6
Project analysis 7
Simulation problems 9
Explore the risk 9
Understanding crowd risks 10
Research background 11
Risk management 12
Improving crowd safety 12
Safe little world 13
Crowd management 13
Who are the end users of crowd simulation? 14
Realising the problem 14
Safety budget 14
Prices driven down 15
v
vi Contents
Not the way to go 15
New objective 16
Understanding the problem 16
Safety-critical systems 16
Towards a standard 17
Capturing information 18
Understanding the audience 18
Learning from past experience 19
Event planning 20
Risk assessments 20
Reality hits home 21
The root of the problem 22
Vision and imagination 23
A new approach 24
Simulations were not the way forward 24
Research revisited 25
Cost-effective crowd safety modelling 25
Conclusions 26
2 Crowd risk analysis 27
Introduction 27
Basic planning/approval requirement 30
Missing skills 31
Basics 31
Understanding the basic skills 32
How much space do crowds need? 32
Why is this a problem? 32
Standing and moving space requirements 32
Body space 33
Body ellipse 34
Event guidance 34
Standing crowd density 35
Average area for a person 35
The toss of a coin 37
Defining risks 38
The minimum is not enough 40
Illustration of crowd density 40
Higher-density crowds 41
Freedom of choice 42
Upper limit established 43
Contents vii
Crowd risks 43
Shockwaves 44
Keep the crowd density low 44
Average individuals 45
Guidance: Single values 45
Control density to reduce risks 46
Calculating area: A problem 46
Two types of space 47
A bigger picture 47
Two people per square metre 50
Density perspective illusion 50
Space filling 51
Moving crowds 51
Sounds too simple! 53
Standing and walking profiles: Another string experiment 54
Graphing the results 58
Nothing new 59
Doomed to repeat past mistakes 60
Site design 60
Space utilisation 60
Better references 61
Dangerous crowd simulations 61
Defining ‘risk’ due to density 61
Conventional risk assessment 62
Qualitative and quantitative risk analysis 63
3 Causality 65
Introduction 65
Crowd disasters 66
Notes on incidents 66
Planning, approval, operations 66
Planned events 69
Historical review 70
Patterns of failure 70
Causality 71
Definitions 71
Causation: Comparing scientific and legal definitions 71
Risk and certainty 71
Problems lying in wait 73
Proximate and distal causality 74
viii Contents
Event legislation 75
The Licensing Act 2003 76
Negligence 77
Definitions 77
Defining crowd disaster causality 78
Causes of accidents/incidents 79
Site design: theory 79
Investigating a major incident 80
Probability of harm 81
Crowd forces 81
Reasonably foreseeable 82
Site capacity 82
Entry and exit points 82
Movement pathways 83
Site design: Pinch points 83
Underlying causality 84
Plan for the worse case 85
Overcrowding incidents 85
Throughput incidents 85
Crowd and event modelling 86
4 Crowd science 87
Introduction 87
Not how we would do it! 88
Lessons from the workshops 89
The problem with simulation 90
Why had this happened? 90
Modelling 90
External influences on crowd behaviour 91
Deadly consequences 92
Crowd dynamics and crowd science 92
Simulation danger 94
Nice to look at: But is it real? 94
Caveat emptor 95
Crowd science: The bigger picture 95
Risks and hazards 96
Crowd hazards 96
The purpose of a model 98
Are all crowd simulations bad? 98
After the event! 98
