What Traffic collision reconstruction mean?
Vehicular accident reconstruction is the scientific process of investigating, analyzing, and drawing conclusions about the causes and events during a vehicle collision.
Reconstructionists are employed to conduct in-depth collision analysis and reconstruction to identify the collision causation and contributing factors in different types of collisions, including the role of the driver(s), vehicle(s), roadway and the environment.

The laws of physics and engineering principles such as the conservation of linear momentum, work-energy methods, and kinematics are the basis for these analyses and may make use of software to calculate useful quantities.

The accident scene
Scene inspections and data recovery involve visiting the scene of the accident and investigating all of the vehicles involved in the collision.
Investigations involve collecting evidence such as scene photographs, video of the collision, measurements of the scene, eyewitness testimony, and legal depositions.

Additional factors include steering angles, braking, use of lights, turn signals, speed, acceleration, engine rpm, cruise control, and anti-lock brakes.
Witnesses are interviewed during accident reconstruction, and physical evidence such as tire marks are examined.