Accident Reconstruction: A Glossary for Personal Injury Attorneys

Helping attorneys address vehicle accident cases

Accident reconstruction (sometimes referred to as crash or incident reconstruction) is a vital component in personal injury cases, providing crucial insights into the events leading up to an incident. However, navigating the terminology of forensic engineering can be a little daunting.

In this post, we aim to demystify accident reconstruction by providing a comprehensive glossary of key terms. Whether you’re a seasoned legal professional or just starting in the field of personal injury law, this guide will equip you with the foundational knowledge needed to effectively engage with forensic engineers and understand their reports.


Accident Reconstruction: The process of analyzing available evidence to determine the sequence of events leading to an accident, often involving the use of engineering principles, physics, and mathematics.

Forensic Engineer: A licensed professional who applies engineering principles to investigate accidents, analyze evidence, and provide expert testimony in legal proceedings.

Kinematics: The study of motion, including the trajectory, velocity, and acceleration of objects involved in an accident.

Collision Dynamics: The analysis of forces and interactions between vehicles, pedestrians, and other objects during a collision.

Vehicle Dynamics: The study of how vehicles respond to driver inputs, road conditions, and external forces, including factors such as braking, steering, and stability.

Human Factors: The study and analysis of how human characteristics, behaviors, and limitations contribute to the occurrence, dynamics, and outcomes of traffic accidents.

Coefficient of Friction: A measure of the grip between tires and the road surface, influencing braking distance and vehicle maneuverability.

Black Box (Event Data Recorder): A device installed in many vehicles to record data related to vehicle speed, acceleration, braking, and other parameters in the moments leading up to an accident. See our complete list of vehicles available for EDR download here.

Occupant Kinematics: The study of how occupants move within a vehicle during a collision, including factors such as seatbelt usage, airbag deployment, and potential injury mechanisms.

Time-Distance Analysis: A method used to reconstruct the movements of vehicles involved in an accident by analyzing time intervals and distances traveled between key events.

Crush Analysis: The examination of vehicle damage patterns to estimate the severity and direction of forces involved in a collision, aiding in the reconstruction of events.

Pedestrian Projection/Throw Distance Analysis: The examination and calculation of the distance a pedestrian is projected or thrown as a result of being struck by a vehicle.

Conservation of Momentum: A fundamental principle in physics stating that the total momentum of a closed system remains constant before and after a collision, often used to calculate vehicle speeds and directions.

Conservation of Energy: The physical law that energy cannot be created or destroyed, only transformed from one form to another. This principle is used to analyze the dynamics of a collision and reconstruct the events leading up to and following the accident.

Delta V: Often denoted as ΔV, is a crucial concept in accident reconstruction referring to the change in velocity experienced by a vehicle or object during a collision. It is calculated by subtracting the initial velocity from the final velocity, taking into account both the magnitude and direction of the change.

Principle Direction of Force: The primary direction in which the force is applied during a collision.

Photogrammetry/Videogrammetry: The use of photographs and videos to create scaled diagrams and three-dimensional models of accident scenes, facilitating detailed analysis and visualization.

Understanding the terminology of accident reconstruction is essential for personal injury attorneys seeking to effectively advocate for their clients. By familiarizing themselves with these key terms and concepts, attorneys can better communicate with forensic engineers, assess the strength of evidence, and present compelling arguments in court.