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

2. Possible Perception and Perception Scanning Ahead to Identify Hazards

3. Possible Perception- Limited by Highway Geometry

4. Possible Perception & Perception- Limited by Topography

5. Encroachment into an adjacent lane

6. Start of Evasive Action

7. Initial Contact and Maximum Engagement

8. Distributed Concentrated Maximum Engagement

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

10. Elements of Investigation: “H-V-E”

11. 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

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

13. 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

14. 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

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

16. Vehicle Factors

17. 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

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

19. Vehicle Damage – Impact Angle

20. Vehicle Damage – PDOF and Overlap

21. Vehicle Damage – Occupant PDOF

22. Vehicle Condition – Loading

23. Environmental Factors

24. 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

25. 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

26. Environment – Physical Evidence

28. Environment – Highway Geometry

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

30. Environment – Weather Conditions How far could you see?

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

32. 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