Tab #2 Elements of a Traffic Crash Elements of Investigation Interview Techniques

Possible Perception and Perception Scanning Ahead to Identify Hazards

Possible Perception- Limited by Highway Geometry

Possible Perception & Perception- Limited by Topography

Encroachment into an adjacent lane

Start of Evasive Action

Initial Contact and Maximum Engagement

Distributed Concentrated Maximum Engagement

Final Rest Classify by How the Vehicle Arrived at Its Final Resting Point

Elements of Investigation: “H-V-E”

Factors and Conditions Relating to the Crash… Before Crash During Crash After Crash Human Vehicle Environ- ment Behavior Condition Impairment Passenger(s) Occupant Motion Seat belt usage? Behavior Personal Injury Passenger Injury Driver Interview

Human Factors A Focus on the Role that Humans Have Drivers and passengers Witnesses Response personnel

Human Factors Focus on the Driver and Passenger Identification and contact information Basic Review of Incident Injuries Received What alerted them to the impending crash

Human Factors Focus on Independent Witnesses Identification and contact information What they saw Where were they when they saw the crash What alerted them to the collision Any relationship to accident participants

Human Factors Focus on Response Personnel Fire Department EMS Personnel Law Enforcement Personnel Motor Carrier Enforcement Personnel Tow truck drivers News Media (photojournalists, TV)

Vehicle Factors

Factors and Conditions Relating to the Crash… Before Crash During Crash After Crash Human Vehicle Environ- ment Angle of Impact Speed at Impact Position at Impact Vehicle Design Pre-trip Inspection Load Securement Exterior Damage Interior Damage Occupant Ejection Final Rest

Vehicle Vehicle dimensions, specifications, equipment and load Vehicle damage Direct or contact Indirect or induced Undamaged areas Vehicle mechanical condition

Vehicle Damage – Impact Angle

Vehicle Damage – PDOF and Overlap

Vehicle Damage – Occupant PDOF

Vehicle Condition – Loading

Environmental Factors

Environment Focuses on the general area where the crash occurred Includes the physical evidence at the scene that was created prior to and from the collision Includes the highway geometry Includes the weather conditions

Factors and Conditions Relating to the Crash… Before Crash During Crash After Crash Human Vehicle Environ- ment Damage to Road Impact Location Direction of Travel Highway Design Surface Condition Time of Day Traffic Control Dev. Physical Evidence Debris Tire Marks Gouges

Environment – Physical Evidence

Environment – Highway Geometry

Documenting Highway Geometry Lane and shoulder Widths Grade Curvature Cross-slope Hwy Fixtures Surface Condition Traffic Control Devices Land Use Topography Surface Type

Environment – Weather Conditions How far could you see?

Environment- Road Surface Condition Document the presence of snow, snow-pack, ice and evidence of sand/salt/plowing activities on the highway.

Interviewing Prepare for the Interview Outline or Script Areas of Questions Identify the “who, what, when, where and how” questions that you will be asking Listen During the Interview