Whether it’s a minor collision or a product liability case, crash reconstruction means helping our clients objectively understand who or what failed, and how, to result in a crash between motorized vehicles and/or fixed objects.
Crash reconstruction — which, just as it sounds, is all about reconstructing a crash for litigation purposes — answers the main question of how a collision occurred, and often supports our broader crash investigation and reconstruction work with answers to questions like these:
- How fast were one or both cars going?
- If it was a two-way single-lane road, who crossed the center line?
- Were their headlights on?
- Were they wearing their seatbelt?
- Were they texting or otherwise distracted?
Here’s how the process looks for us here at Kittelson LLC.
Step 1: Reading the Scene
It starts with using investigative skills to read the scene. Typically, as soon as we learn what kind of vehicles were involved, we know what kind of information we’ll need to identify and gather. We capture photos of clues in the road, like fluid debris, tire marks, scrapes/gouges, and police officer’s paint, before moving on to more advanced tools.
Grade rods (essentially a giant ruler) are a quintessential piece of equipment for any reconstructionist — they show scale in photographs of vehicle damage and make it easier for a layperson to understand. A newer technology is the FARO 3D scanner, which we use to map the scene and vehicle digitally and preserve the image. Laser scanning collects millions of data points in a fraction of the time of traditional measurement methods and produces a point cloud that can be imported into computer software for analysis. We can take these scans roadside or at a lot where the vehicles are being stored.
Step 2: Downloading the Vehicle Data — Event Data Recorders (the “Black Box”)
An Event Data Recorder (EDR) in a passenger vehicle — commonly called a “black box” — is a device that records data parameters related to a crash, triggered by a deployment or non-deployment level event. These systems can capture crash data such as speed, brake switch status, engine RPM, and seat belt usage, along with other parameters. Heavy vehicle Engine Control Modules (ECMs) can also record event data pertaining to a crash, which we’re able to extract.
Beyond the vehicle’s own EDR, we can gather supporting data from personal GPS devices, fleet-tracking systems, and dash cameras to strengthen a reconstruction.
Step 3: Modeling the Crash in CAD & Reconstruction Software
We bring all this information back to the office and analyze it using CAD and reconstruction software. We start with the final rest position (full stop) after the crash and work backwards to build a sequence of pre-impact, impact, and post-impact events, modeling how the vehicles made contact — from first contact to maximum engagement — using their damage profiles.
Step 4: Running the Calculations
We run scientific equations on the data to answer the questions being asked. The most common question is how fast one or both cars were going before the collision, but it’s remarkable how much information is available. For example, we’ve determined that a truck driver was using social media on his phone at the time of a crash by analyzing his mobile data usage — the same kind of driver behavior and human factors analysis we apply across our forensic work.
Step 5: Reporting Findings & Expert Witness Testimony
Finally, we share our findings. We may write a technical report for our clients and are sometimes called upon to testify in court about that report.
Why Our Process Matters as Much as Our Technology
The technical steps of this process are important for conducting an accurate investigation, but we believe the way we approach the process is just as important. We’re dealing with sensitive situations, and we’re hired to provide unbiased, factual information. Many of Kittelson LLC’s clients find us through word of mouth because we’re committed to doing good work and being honest and unbiased. We also think it’s important to have the technology and training to keep the whole process in-house, rather than outsourcing components — see our full technological capabilities for more on the tools behind this process.
Frequently Asked Questions
What is an Event Data Recorder (EDR) and what does it record?
An Event Data Recorder, or “black box,” is a device built into most modern passenger vehicles that records data around the time of a crash — including speed, brake switch status, engine RPM, and seat belt usage. Commercial vehicles use a similar system called an Engine Control Module (ECM). Reconstructionists download and analyze this data as one of the first steps in rebuilding a crash.
How do investigators determine how fast a vehicle was going before a crash?
Speed is calculated using a combination of physical evidence (tire marks, crush damage, final rest position), 3D scene and vehicle scans, and Event Data Recorder data where available, run through CAD and reconstruction software and validated against established engineering formulas.
Can crash reconstruction determine if a driver was texting or distracted?
Yes. By analyzing phone records, mobile data usage, and vehicle data alongside the physical evidence, reconstructionists can often determine whether a driver was using a phone or otherwise distracted at the time of a crash.
How long does a crash reconstruction take?
Timelines vary by case complexity, but the process generally follows the same sequence: scene and vehicle documentation, data downloads (EDR/ECM, GPS, dash camera), CAD modeling and analysis, and a final written report — with expert witness testimony as needed for deposition or trial.
It’s always interesting for me to explain to people outside the world of forensic transportation engineering what I do. Once I get through a few layers of explanation, people usually respond with, “So you’re the CSI guys?” We may not have our own TV show (yet!), but I suppose some of the principles are the same.
If you’d like to discuss this topic further, please don’t hesitate to reach out to me — Nicholas Schlechte, nschlechte@kittelson.com.