Title: Modelling and Managing Crowd Behaviour
1Modelling and Managing Crowd Behaviour
- Prof. Dr. G. Keith Still FIMA
- Easingwold February 2008
2Contents of this talk
- Crowd Dynamics
- DIM-ICE
- Models and Simulations
- Large Scale Multi-Building Evacuation
- Communicating with the Crowd
- Canary Wharf Project
- Summary and Conclusions
31. Crowd Dynamics
- Design Information Management
- Ingress Circulation - Egress
4Three phases of Crowd Dynamics
- Ingress
- Arrival profile and flow rates
- Assessing the design capacity/constraints
- Signage/communication system
- Circulation
- Facilities planning and management
- Signage/communication systems
- Egress
- Normal and emergency
- Signage/communication systems
5DIM ICE model for Crowd Dynamics
6Simulation of doorway entrance
The addition of a central handrail changes the
dynamics of the crowd This can INCREASE flow rate
through the door by between 35 -
70..... Small change in the design and we have a
significant change in the flow rate
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8Flow Rates NOT constant
- As DENSITY increases FLOW RATE will increase THEN
decrease - As the crowd density approaches the critical
values of 3-4 people per square metre the flow
rate drops - This is critical in designing emergency egress
routes. - At high density the crowd moves at the speeds of
the slowest group in the crowd - Simulations need to reflect this
92. Models and Simulations
- Since 9-11 literally hundreds of emergency
evacuation models, simulations and tools have
appeared on the market. - Some good, some bad, some downright dangerous.
10Modelling for crowd safety
- Someone who builds a mathematical model can get
carried away with all the clever things that can
be done with it. - The model becomes a safe little world, free from
anxiety, free from office politics, rewarding in
its own right. - This often results in a very clever model that
has little to do with reality. - Resist the temptation to be too smart in building
a model. Take small model building steps
interspersed with healthy doses of reality. - Sam. L Savage. Author of Insight.XLA - Analysis
software.
11Dont let simulations fool you
- Watch the next two video clips of commercial
evacuation software.
12Simulation 1. Steps
13Simulation 2. Simulex
14Discussion 1
- Discuss the pros and cons of the last two
simulations
15Models help us test the design dynamics
- We build a model to discover the properties of a
system - With discovery comes understanding
- With understanding comes control
16Mathematical Modelling Tools
- Spatial Analysis
- Visibility Graph Analysis
- Spatial and temporal invariants
- Network Analysis
- Optimisation - Min/Max Flows
- Tours, shortest spanning trees, etc.
- Agent Based Analysis
- Emergent Behaviour
- Sematectonic Stigmergy change in state, result
of task-related action, progressive crowd collapse
17DCMS Persistent Standing
18Progressive Crowd Collapse
19Large ScaleMulti-Building Evacuation
- Consider the elements of evacuation and business
continuity for a large scale, multi-site,
multi-building evacuation,
20World Trade Centre - 2001
- Twin Towers
- 9 Million Sq. Ft.
- 110-story Buildings
- 50,000 employees
- 80,000 daily visitors
- 104 Elevators
- 9 building evacuations
2116 Acres of devastation
22Precision Attack multi-building evacuation
23Project Canary Wharf
- London Financial District
- 90,000 residents
- Island within city of London complex space
24Canary Wharf CBD
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264 Egress Scenarios post 9/11
- Total Evacuation
- Fire (GTFOH)
- Directed Evacuation
- Bomb threat
- Phased
- Decontamination
- Stay Put
- External threat (Biological, Chemical,
Radiological, Gunman, Security alert, Car bomb.)
27Consider the location of safe refuge areas
28Discussion 2
- What are the key elements in defining a
multi-building evacuation? - Where would models help us understand the crowd
dynamics and evacuation strategy?
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30Note centralised assembly points
31Evacuation in stages
- Floor to safe passage (stairs)
- Stairs to ground floor
- Ground floor to streets
- Multi-building street evacuation
32Possible Strategic Responses
33Evacuation Strategies
Analysis
Planning
Implementation
Consulting
Strategic detailedanalysis
Scenario Planning
Training Mgrs
Training Individuals
Data capture
Tools Software
Communication decision support e.g.,
Evacuation tool
Evacuation Tool
Spreadsheets Myriad
Spreadsheets Myriad
Spreadsheets
Canary Wharf the UK Financial District
34Network Diagram
35Capacity Analysis
- Bottleneck analysis
- North 17m
- East 19m
- South 27m
- West 37m
- Total 100m
- 82 people per metre per minute
36Egress Capacity 100m 8,200 ppm
37The estate has sufficient capacity (roads)
38Passes Rough Cut Modelling
- Now we drill deeper into the problem
- Are there other limits to egress?
39Simulating egress - choice of four exits
40Clearing a floor
41Stair Egress - considered as safe
- Data shows stairway congestion problems
- Precedence behaviour
- People stopping to rest
- How fit is the population?
- First responders trying to gain access while
egress is in progress - 15 story building
- 9 minutes to descend stairs
- First responders could be on site in 5 minutes
42Are there other site limits?
- Which route would the public choose?
- Are there any areas that give rise to potential
crushing?
43Egress is directional
- Colours show allocation to each exit
- In the event of an incident egress away from the
incident is still divergent, unidirectional and
avoids cross-flows
44Simulations problem spotter
- What do the above images tell us about the crowd
dynamics? - What do we need to do to keep this crowd safe?
45Unplanned Egress
Dangerous bottlenecks at the Station Approach
46Evacuation Strategies
Analysis of complex spaces and behavioural based
safety
4750,000 copies deployed
48Crowd movements
- In large areas how quickly can the crowd
disperse? - Using GIS systems we can map mass migrations
49London resident population densities
50Walk-time information is available
514. Crowd Communications
- How do we get the crowd to START to move
- Information systems, communication strategies.
52"The chief virtue that language can have is
clearness, and nothing detracts from it so much
as the use of unfamiliar words."Hippocrates
53Four Seasons Hotel (Channel 2)
- Do not, under any circumstances, use the
elevators - Many people evacuated from the World Trade centre
used the elevators - Stay Put. You will be advised as to what
procedures to undertake - Communication problems
- Do not open windows - a sudden surge of fresh
air will create a vacuum which will attract fire.
54Jargon is not good communication
- Hillsborough / Centennial Park
- Silver Control / Orange Car Park
- Ambulance ... loading point / rendezvous point /
pickup point - Left / Right
- Main Entrance / Inner Concourse / Main Stage
- DS1 / 19 North Promenade / HSBC Building
55Initial stages of a disaster
- Chaotic, confusion, media reports confused
- What happened?
- Where did it happen?
- What do I do?
- Where do I go?
- What next?
56Do crowds always panic?
- How the crowd reacts depends on a number of
critical factors.
57Behaviour described as panic
- People do not use nearest emergency exit
- escape via way in
- May not use emergency exits at all
- not noticed
- unfamiliar location
- Frantic escape activity
58Panic happens when people are
- Trapped
- exit blocked
- late evacuation
- Disoriented
- building collapse/capsize
- dark/smoke filled environment
- Isolated from others
- family/friends
59But panic.
- Is not inevitable
- Is an individual response
- Is rare in emergencies
- Can be mitigated
- Discuss how we can mitigate panic in the built
and complex environment
60May 18th Panorama BBC
61Crowd Dynamics - technical advisors
- It would take some time to realise this was a
simultaneous attack - Total failure of the London Underground Network
- City Wide problem with traffic
- Massive Grid Lock
- Multi-site evacuation
- Canary Wharf no transport off the island
- Short term impact on public confidence in the
system - Potential for the crowd to be overreactive
62Discussion 3
- Do we address these factors in current planning?
- Could we improve our evacuation strategies?
635. Summary and Conclusions
64Phases and Controls
- Three phases of Crowd Behaviour
- Ingress Circulation Egress
- Three influences of Crowd Dynamics
- Design Information Management
- Modelling helps
- Discovery Understanding Control
65 Foresight NOT Hindsight