Looking Backward, Thinking Backward: Hindsight Judgment of Human Error in Transportation Accidents P

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Looking Backward, Thinking Backward Hindsight
Judgment of Human Error in Transportation
Accidents- Part II
18th National Conference on Rural Public and
Intercity Bus Transportation October 20, 2008
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John Goebelbecker, P.E.

• Partner of Foresight reconstruction, Inc. Morton
  Grove, IL
• Master of Science in Aerospace and Mechanical
  Engineering, University of Notre Dame
• Consultant in Vehicle Accident Reconstruction

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• What is hindsight bias?
• How does it relate to reconstruction of crashes?
• Case studies for discussion.

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Hindsight Bias

• Your definition.
• The tendency for post-crash observers to falsely
  believe that the once-future incident was more
  foreseeable for those involved than actually was
  the case.
• Those who know how things turned out have
  trouble believing others didnt see what was
  coming. Fischhoff, 1975

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Recognizing Hindsight Bias

• Post-crash data set vs. Pre-crash data set
• Counterfactuals (hypotheticals)
• Conditions vs. Causes

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Pre-Crash v. Post-Crash Data
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An Unfortunate Tail
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• Officer Mullen of Chicagos MAI Team responds to
  a 911 call and learns the following.

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• John was driving his teenage daughter, Brigit,
  and trusted friend, Caera, to a soccer game when

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Brigits Perspective

• Brigit saw the squirrel from ½ block away and saw
  it looking across the street at a corn cob
  feeder.
• Squirrel ran out from right to left.
• John swerved left.
• John should have reacted sooner.
• John should have braked.
• Johns fault.

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Caeras Perspective

• Squirrel had it coming to him.
• Squirrel not in cross walk.
• John had no time to react.
• John did everything he could to avoid.
• Squirrels fault.

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Johns Recollection

• Driving 15 mph (Had just looked down at the
  speedometer.)
• Saw the squirrel when it had just stepped onto
  road from neighbors yard on right.
• Moving right to left.
• Squirrel not looking for approaching traffic.
• Swerved left to avoid.

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MAI Report

• 10 feet lane width
• Right front tire ran over tail.
• Car traveling 17 mph (from electronic data
  recorder)
• Typical squirrel runs at 10 fps and can change
  direction in .5 s.
• Kinematic analysis reveals the following

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Outcome Matrix
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Hindsight Reconstruction

• Conflict could have been avoided had driver
  reacted differently.
• Conflict could have been avoided had the driver
  reduced speed and paid closer attention to
  squirrel before emergency.
• But for the drivers conduct, the squirrel lives
  to see another spring.

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Foresight Reconstruction

• Driver had multiple attentional demands prior to
  crash.
• Driver was acting reasonably prior to crash.
• Movements of the squirrel were uncertain.
• Time to perceive and react was short.
• Response to left is natural.

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Officers Conclusions

• John did not maintain proper lookout.
• John should have sounded horn.
• If John reacted 1/2 s sooner, squirrel would not
  have been struck.
• Johns response to steer left was improper.
  (Never cross centerline!)

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Behavior Judged by Outcome

• Caera satisfied with Johns response (good
  outcome).
• Brigit critical of Johns response (typical
  teenagers view of parent).
• Neither should judge Johns response by outcome.

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Standard for Drivers Conduct

• The actors conduct must be judged in the light
  of the possibilities apparent to him at the time
  and not by looking backward with wisdom born of
  the event
• Driver must act with ordinary care the care
  a reasonably careful or prudent person would use
  under circumstances similar to those shown by the
  evidence.

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• A person faced with an emergency and who acts
  without opportunity to consider the alternatives
  is not negligent if he acts as a reasonably
  prudent person would act in the same emergency,
  even if it later appears that he did not make the
  safest choice or exercise the best judgment. (New
  York Emergency Doctrine)

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Your Opinions?

• Where can hindsight bias influence causal
  analysis?
• Does the homeowner who feeds the squirrels share
  some responsibility?
• Does the city share some responsibility?
• Does Brigit share some responsibility?

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Other Fact Patterns

• John never saw the squirrel and did not stop
  until Brigit screamed.
• Squirrel was sitting in roadway eating acorns.

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Break
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