Simulating Dynamical Features of Escape Panic

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Simulating Dynamical Features of Escape Panic

• Dirk Helbing, Illés Farkas, and Tamás Vicsek
• Alex Turek

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Stampedes

• People trying to move faster than normal
• Physical interactions between people
• Uncoordinated passing of bottlenecks
• Arching/clogging at exits
• Dangerous pressures within jammed crowd (up to
  4,450 N/m)

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Stampedes (contd)

• Injured/fallen people turn into obstacles
• Tendency of mass behavior, i.e. herd instinct
• Alternative exits are overlooked or underused

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Studying Stampedes

• Mostly social psychology (mentality of herd
  behavior)
• Helbing et al. attempted to model them using
  self-driven particle systems
• Combine socio-psychological and physical forces

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A Single Particle

• Affected by multiple forces
• Desired Velocity and associated acceleration
• Interaction forces

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Desired Velocity Force

• Helbing et al. specified these parameters
• vi0 (Desired velocity)
• 0.6 m/s Relaxed
• 1.0 m/s Normal
• 1.5 m/s Nervous
• gt1.5 m/s Panic (transition to uncoordinated
  bottleneck behavior)

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Interaction Forces

• Psychological desire to have room between you and
  another person
• Psychological desire to not be too close to the
  walls

F
F
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Interaction Forces

• Body force counteracting body compression
• Sliding friction force counteracting movement
  tangential to something youre in contact with

F
F
F
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Measured Effects Transition to uncoordination
due to clogging

• Arch-like bunching, with avalanche effect when
  arches break (demo)

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Measured Effects Faster-is-Slower Effect

• Attempting to have too high a vi0
• High interpersonal friction becoming the dominant
  force at a bottleneck
• Buildup of forces causing extremely high
  pressures, and injuries (demo)
• Asymmetrical columns can improve outflow and
  prevent buildup of fatal pressures (demo)

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Measured Effects Faster-is-Slower Effect

• Jamming can occur at widening of escape routes
  (demo)

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Measured Effects Mass Behavior

• Individualism vs. Herd behavior
• Each pedestrian may either select individual
  direction, follow avg. direction of his neighbors
  in a certain radius, or a mixture of both,
  weighted by panic parameter pi. (demo)

Desired direction at time t
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Measured Effects Mass Behavior

• Both have drawbacks
• All individualistic means no one will learn from
  anyone else (demo)
• All herding means no exploration for other exits
  (demo)

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Measured Data
Leaving time vs. Desired velocity
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Measured Data
Leaving time for 80 people, given different
combinations of individualistic and herding
behavior
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Questions?

• Cited Paper
• Helbing, Farkas, Vicsek.
• Simulating Dynamical Features of Escape Panic.
  2000
• http//www.eecs.ucf.edu/lboloni/Teaching/EEL6938_
  2007/papers/Helbing-EscapePanic.pdf
• Presentation by Alex Turek