Tab 2 Elements of a Traffic Crash Elements

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

Maximum Engagement Distributed Concentrated

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 Human Vehicle Environment Behavior Condition Impairment Passenger(s) During Crash After Crash 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 n n Identification and contact information Basic Review of Incident Injuries Received What alerted them to the impending crash

Human Factors Focus on Independent Witnesses n n n 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 n n n 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 Environment Vehicle Design Angle of Impact Exterior Damage Pre-trip Inspection Speed at Impact Interior Damage Load Securement Position at Impact Occupant Ejection Final Rest

Vehicle dimensions, specifications, equipment and load Vehicle damage n n n 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 Environment Highway Design Physical Evidence Damage to Road Surface Condition Debris Impact Location Time of Day Tire Marks Direction of Travel Traffic Control Dev. Gouges

Environment – Physical Evidence

Environment – Physical Evidence

Environment – Highway Geometry

Documenting Highway Geometry Topography Land Use Hwy Fixtures Grade Lane and shoulder Widths Surface Condition Curvature Cross-slope Traffic Control Devices 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 n n Outline or Script Areas of Questions Identify the “who, what, when, where and how” questions that you will be asking Listen During the Interview