From train derailments to car crashes, accidents happen all the time. Whether those accidents are litigated in court, however, is a different story. Even the seemingly most straightforward accidents can present complex, multi-faceted issues of negligence, and it may not always be readily apparent which party, if any, is at fault. An accident reconstruction specialist, as the name suggests, can recreate the scene in a way that answers unknown questions about the incident. In other words, an accident reconstruction expert can explain each part of the event, step-by-step, to the jury. In many accident cases, their testimony can be an invaluable tool for both the plaintiff and defendant.
What is an Accident Reconstruction Expert?
Accident reconstruction is a branch of causation forensics that uses science to determine the circumstances of an accident. They are most often retained in traffic collisions involving automobiles, motorcycles, trucks, buses, and pedestrians but can be used in an array of different scenarios. They utilize principles of mathematics, physics, and engineering to conduct an analysis of the accident. From these principles, they can form opinions as to velocity, collision angles, driver visibility, and other causal factors of the accident.
There are many benefits to an accident reconstruction expert. First, these experts possess the ability to quantify and measure aspects of the accident, such as speed, to an estimate far more precise than a layperson could. Secondly, even if an accident had several eyewitnesses, eyewitness testimony can be unreliable, as memories often dissipate over time and can be subconsciously influenced by various cognitive biases. Likewise, it is normal for a person to not clearly remember the moment of an accident, as emergency situations and the spike in adrenaline can cause memory lapses. This phenomenon of the human brain during survival mode and its tendency to create unreliable memories can partially account for the conflicting explanations of so many accidents. The goal of the accident reconstruction expert is to take away these uncertainties, and recreate an objective narrative of what happened.
How Do Accident Reconstruction Experts Form Their Opinions?
Ideally, an accident reconstruction expert’s work begins at the time of the accident, or as close to it as possible. There can be critical evidence at the scene, so the sooner the expert can evaluate it, the better. Failing that, photographs and video surveillance of the accident can also suffice. In the case of a car accident, for example, evidence such as tire marks, impact marks, roadway surfaces, metal debris, and airbag control modules (the “black boxes” which sometimes store data on speed and other variables) are critical pieces of the puzzle. Of course, most experts will not be retained until well after the time of accident, which is why it is important to preserve as much of the evidence as possible. Obtaining photographic evidence or video surveillance footage of the incident can greatly help in the expert’s preparation.
Whether the case involves a car, truck, motorcycle, bus, or any other mode of transportation, an inspection of the vehicle needs to be conducted. Inspecting a vehicle can help obtain a bevy of information, such as the speed, angle, and severity of impact. A vehicle may also contain human hair, skin, and blood that can provide insight as to the driver and passenger movement.
Once provided all necessary evidence, the reconstruction can begin. An accident reconstruction expert uses the principles of mathematics and physics to determine the circumstances surrounding the accident, and by extension, whether a party was negligent. The speed of a vehicle, for example, is typically a critical piece of information. When determining the speed of a vehicle, there are several methods an expert can employ. Energy analysis refers to the mathematical description of the vehicle’s speed and weight. A vehicle’s “kinetic energy” or “motion energy” is decreased by factors such as the road surface and vehicle damage. A vehicle’s energy can also be transferred upon impact to other piece of property (i.e., a car hitting into a wall or utility pole). The speed of a vehicle pre-impact – an important factor when determining driver negligence – can be mathematically calculated by figuring out the energy loss of each factor, such as the road surface, and then adding the equivalent speeds of all factors to find the “combined speeds equation.” Because some energy cannot be quantified, the combined speeds equation typically yields the minimum speed of the driver.
Other methods of speed analyses can be employed by an expert such as conducting a drag factor analysis (an evaluation of skid mark length) or a crush analysis (a replication of the accident on the point of impact to compare damage). Speed can also be determined by looking at the point of impact of a piece of property (i.e., a utility pole) and calculating the typical breaking point of an object of that particular size.
As the speed, position, and time of a vehicle are all interrelated, a time distance analysis is another methodology that can be used to determine numerous factors surrounding the accident such as, the initial distance from the impact, the time available for action and to avoid the collision, and any potential reaction delays or inattentiveness of the driver.
Aside from the speed and distance calculations, a qualified accident reconstruction expert should be able to testify to all aspects of the accident, including a driver’s visibility. Factors to consider include: the weather, lighting conditions, illumination of the vehicle (and the party’s location in relation to said illumination), and if there were any visible signs or warnings of the oncoming vehicle.
The Expert’s Testimony at Trial
A qualified expert should be able to accurately employ the aforementioned means of analyses in forming their opinion as to the accident. When presenting their opinions at trial, an expert’s testimony, as always, should meet the qualifying standards set forth in Daubert. That is, the expert’s theory should be tested for reliability, with appropriate maintenance of standards and controls and a known potential rate of error. Further, the techniques employed by the expert should be, when possible, subject to peer review and publication and generally accepted within the community of accident reconstruction specialists. Particularly because a majority of the work entails experimentation and the recreation of accidents, it is important that the expert’s testing be based on reliable methodologies, precise measurements, and accurate information. An expert’s opinion should never be based on speculation or conjecture.
Even if professionally qualified, an expert still needs to be able to communicate their findings in a clear, concise manner so that the jury fully understands the circumstances surrounding the accident and why a party was (or was not) negligent. Particularly because so much of the testimony is couched in mathematical principles, it is important to maintain a human, pragmatic element to the testimony so that the jury can properly conceptualize the data.
With technology in the courtroom becoming more mainstream, experts should take advantage of the array of demonstrative aids that can better illustrate the accident to the jury. Three-dimensional mapping of the accident or even virtual reality programs can help in recreating the accident in ways that testimony cannot.
Overall, as the use of accident reconstruction experts become more ubiquitous, the chances of an adversary retaining one also increases. Thus, it is all the more important to ensure that you retain a qualified expert to prove your case, establish your defense, or counter the opinion of your adversary’s expert.