Collision Reconstruction

Discovery Questions

General Collision Information

Where and when (date, time) did the collision occur? How many vehicles were involved? What directions and in what lanes were the vehicles traveling before impact? Where did impact occur? How did the vehicles collide?

Vehicle Information

What is the year, make, model and configuration (2 door, hatchback, etc.) of your vehicle? Was your vehicle operating properly? Was it stock or modified? How was it modified? When was it last serviced? What was repaired? Describe any preexisting damage or ask for photographs.

Occupants and Cargo

How many occupants were in your car? Who were they and where were they seated? How much did each occupant weigh? Was there cargo in your vehicle? How much did it weigh and where was it located?

Pre-Impact Conditions

How fast were you traveling at impact? How fast were the other vehicles traveling? What is the speed limit? What was the other vehicle doing before the collision (turning, accelerating, etc.)? Were you confused by its actions?

Pre-Impact Reactions

Did you react before impact? Describe your reaction (brake/steer). How far before impact did you brake/ steer? Which direction did you steer? Did you leave skid marks on the road before impact? How long were the skid marks?

Post-Impact Motion

Describe what happened to your vehicle after impact. Did your vehicle spin? Did you hit another vehicle or roadside object? Were there marks on the road after impact?

Vehicle Rest Positions

Where did your vehicle come to rest? What direction was it facing? Describe or sketch the location and orientation of each vehicle at rest. Were any vehicles moved after they first came to rest? Were any of the tires fl at or damaged?


What were the weather conditions? Was the road surface dry/wet/snowy/icy? Was it light/twilight/ dark? Were your headlights or windshield wipers on?

Contributing Factors

Describe any factors you believe contributed to the collision. Explore each factor in detail. Consider sight obstructions, road design, glare sources, illumination levels, distractions inside the vehicle (children, pets, phones, other electronic devices, etc.) and distractions outside the vehicle (another collision, animals, etc.).

Miscellaneous Information

Do you have any photographs of the scene or vehicles? Do you know of any witnesses? Did you provide a statement to anyone? If so, to whom?

Key Sources of Evidence

  1. Examination of the vehicles and scene soon after the collision.
  2. Police photographs, measurements, scene drawings/sketches and investigation reports.
  3. Repair estimates and vehicle damage photographs from insurance companies or repair shops.
  4. Witness statements, sketches and photographs.
  5. Specialized reports from a mechanic, road design engineer, weather office, etc.

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