Category : Uncategorized

Was it Road Rage? Can an Engineering Analysis Answer That Question?


Justin P. Schorr, Ph.D, Principal Collision Reconstruction / Transportation Engineer ::::

A collision occurred when a school bus moved from the right lane of a limited access highway onto the rightside shoulder and contacted a disabled vehicle. It was dark and the disabled vehicle on the shoulder was not illuminated. The operator of the school bus testified that a tow truck located in the lane to his left executed a lane change, forcing him off the roadway and onto the shoulder into the disabled vehicle. The operator of the tow truck testified that the disabled vehicle was his intended “pickup,” but as he went to move from the center lane to the right lane to access the disabled vehicle, the school bus was trying to squeeze by him by passing him on the right, resulting in the collision.

Two forms of event data were available for analysis – video from the tow truck and engine control module data from both the tow truck and the bus. This data allowed for an accurate plotting of the speed of both vehicles prior to and at the time of the incident. Since the vehicles occupied the same place at the same time during the collision (i.e. the tow truck was touching the bus), the event data could be correlated such that their relative positions leading up to the collision could be plotted to scale. The video data also included a rearview camera making it so the position of the bus in the right lane as it approached the tow truck (which was initially in the center lane) could be seen. This data confirmed the independent correlation and plotting of the speed data from each vehicle.

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Terry and His Drone

Jon W. Adams, Director of 3D Reality Capture ::::

A morning in the life of Terry Myers…

4:00 AM

It is the dead of night. Terry Myers stirs in his sleep, slowly awakening to the theme music from Law & Order. He did not fall asleep with the TV on, watching his favorite show… Instead, this is the ringtone that Terry has assigned to calls that come from his place of business, DJS Associates.

There is an emerging situation which requires a forensic field crew to investigate the scene where a traffic collision has occurred, just hours ago.

4:45 AM

Terry looks over his equipment packed in his Ford Escape (AKA DJS 1), mentally checking boxes, as he accounts for each tool he will need to utilize once he arrives at the scene. DJS protocols states that all site inspections are to include 3D laser scanning, terrestrial photographs and video, measuring wheel measurements, and data captured from a new perspective: the drone.

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Automatic Gate Closes on Man

Automatic Gate

John R. Yannaccone, PE, Senior Mechanical Engineer ::::

Case Synopsis: One evening at closing time, an employee at a self-storage facility opened an electric gate to allow a car to drive out of the facility. As the driver was leaving, he stopped his car in the path of the gate to talk to an employee and a customer. The customer was standing next to the stopped car, adjacent to the gate. Suddenly, the gate began to close and pinned the customer between the gate and the car. The driver moved forward to prevent the gate from hitting his car, but this caused the pinned customer to be twisted between the car and gate, resulting in additional injury.

Expert Analysis: By the time an engineer was retained to investigate the cause of the incident, the storage facility had replaced the gate operator and disposed of the system in use at the time of the incident. Based on the materials provided, the following was determined:

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Independent Recalls and Potential Vehicle Fire Concerns


R. Scott King, Principal Mechanical Engineer ::::

For obvious reasons, the prevention of vehicle fires, both crash and non-crash related, is and always has been a priority at the National Highway Traffic Safety Administration (NHTSA). When needed, NHTSA facilitates – and sometimes mandates – vehicle recalls to remedy potential defects. From identifying emerging failure trends, to providing remedial oversight, to monitoring consumer compliance rates, NHTSA remains an important element in minimizing vehicle fire risk. Recently, NHTSA issued several seemingly independent recalls of over 500,000 Kia and Hyundai vehicles due to potential fire concerns.

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We’ve Expanded All Across the United States

Expert Witness Consulting

DJS Associates’ consulting services has expanded to all across the continental United States, Puerto Rico and Alaska. Whether your case requires a structural engineer in Illinois, a recreational expert in Nevada, a bio-mechanical engineer in New Jersey, or a chemical engineer in Texas, our team is here to provide you with the most qualified consultant to meet your case needs. With professional and technical consultants across the US and beyond, we can quickly respond to collect and document scenes and render reports in a timely fashion. Click Here to see our expanding list of available areas of expertise.

Two Events, One Data Recorder


R. Scott King, BSME, Principal Automotive / Mechanical Engineer ::::

While standing at their property edge, waiting for a school bus, a father and son were seriously injured when they were struck by a passing vehicle that had crossed the opposing travel lane and departed the roadway. The vehicle traveled a short distance after the initial incident and came to a controlled stop in the roadway. Then, after a brief delay, the vehicle accelerated, traveled a short distance, and struck a tree. After the incident, witnesses reported the operator of the impacting vehicle was using her cell phone and appeared confused.

The vehicle operator reported no recollection of the incident and police investigators found nothing to indicate a mechanical malfunction. This conclusion was confirmed by an independent forensic examination, which included downloading data from the vehicle’s Event Data Recorder (EDR). The information from the EDR included five seconds of pre-crash data, as well as a crash-pulse record quantifying the crash severity. This particular EDR could record data associated with only one event. In this case, there were two events: the initial impact with the father and son, and the second with the tree.

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