Passenger Vehicle Accident Reconstruction
Automobile and Light Truck Crash Analysis
The science of accident reconstruction includes principles of physics and fundamentals of engineering. This combination is required in order to fully understand the dynamics of vehicle to vehicle interactions during a crash. Veritech’s forensic engineers have performed investigations and crash reconstructions for thousands of accidents involving passenger cars and light trucks. We utilize state of the art technology, such as vehicle simulation software and “black box” data to assist in determining speeds, impact severity, and motion of the vehicles involved.
Some of the passenger vehicle accidents we have analyzed include issues relating to:
Single vehicle accidents
Low speed accidents
Visibility at night
Visibility during adverse weather
Vehicle safety systems, including airbags (supplemental restraint systems) and seatbelt usage
Light bulb filament analysis, for headlight and brake light illumination
From low-speed collisions to high speed roll-overs and multi-car pile-ups on busy highways, we have the experience and know-how to accurately determine vehicle speeds, delta-V’s, accident sequences and ultimately the factors causing or contributing to the accident.
Analysis of Physical Evidence Related to Accident Reconstruction
After an accident occurs, evidence related to the crash is usually left behind on the roadway within the vicinity of the crash. One example of evidence that is quickly identifiable are tire marks. Tire marks can potentially be used to describe the sequence of events leading up to, during, and after a collision. Tire marks may remain on the roadway for a long time after an accident has occurred, sometimes for even months or years if the marks are not disturbed. Tire marks are one of the main essential pieces of physical evidence that any investigator, forensic engineer, or law enforcement personnel relies upon to help piece together the events of the impact.
Other types of physical evidence typically left at the accident site include roadway gouges, debris fields, paint transfer, engine fluid deposits, and scratches. All of these types of physical evidence can be used to assemble together the accident scenario. Evidence on the roadway can also be correlated to damage to the vehicles involved, further confirming and establishing the sequence of events.
Vehicle Crush Analysis
One of the main methods of accident reconstruction focuses on the damage done to the vehicles involved in an impact. “Crush Analysis” is the study of the deformed body panels and structure of a vehicle to quantify the amount of energy absorbed from in a collision. The amount of energy absorbed can be directly correlated to vehicle speed, as long as justifiable initial conditions are set. An example of a crush analysis would start with an inspection of a subject vehicle involved in a collision. During the inspection, measurements or documentation of the damaged areas are taken.
After the damage is properly documented, an un-damaged vehicle (otherwise known as an “exemplar”) can be inspected to document the dimensions of the vehicle in its uncrushed, undamaged form. Then, the “crush volume” is determined by comparing the uncrushed vehicle to the crushed vehicle. The volume of crush can then be used to quantify the amount of energy absorbed during impact based upon the vehicle’s unique stiffness characteristics. Not all vehicle stiffness values are the same, and thus determining unique quantifiable stiffness “coefficients” is also part of this process. Then, calculating energy absorption based upon the amount of crush aids the forensic engineer in determining impact related information such as speeds and trajectories.
Passenger Vehicle Crash Related Photogrammetry and Videogrammetry
Two common questions related to accident investigation are:
“What if the accident site has changed since the accident happened?”
“What if the involved vehicles are no longer available for inspection?”
Fortunately, not all is lost. If good quality photographs or video taken within the time period of the crash is available, the science of photogrammetry (or videogrammetry) can be used to determine details important to the reconstruction. Video from surveillance cameras, or even dash mounted cameras, can be very helpful in determining vehicle speeds, impact location, points of rest, and other evidence-based data. Photogrammetry allows for a large amount of information to be extracted from standard photographs. When proper documentation is not available or has been destroyed, photographs may be the only piece of evidence left. Fortunately, Veritech has the experience and knowledge to extract this critical data to aid in a successful accident reconstruction.
Passenger Vehicle Condition at the Time of the Accident
In addition to vehicle accident reconstruction, Veritech’s licensed Professional Engineers are also experienced and qualified to assess the condition and operation of mechanical systems associated with automobiles such as braking systems, engine components, steering systems and safety restraint systems such as airbags and seatbelts. Veritech’s engineers have real-world engineering and design experience for many vehicle-based components. This design experience is unique to Veritech and is rare to find within the accident reconstruction industry. It allows our engineers superior expertise when determining if a part or component is defective and may have contributed to an accident. Issues such as design defects, stress based fractures, metallurgical fatigue failures, and thermal cycling failures can contribute to an accident by operation of a defective vehicle.
The condition and proper operation of these mechanical systems may prove to be a significant contributing factor to an accident or to occupant injuries. Our trial-experienced Professional Engineers are well qualified to handle complicated issues and to assess critical investigation points which often arise during the litigation process.