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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


event-data-recorder-crash-data

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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Side-by-Side (SSV) & Watercraft Electronic Event Data


watercraft-event-data-recorder

Robert S. Kinder, Jr., MS, Mechanical Engineer ::::

Over time the number of electronic devices and features in motorized vehicles has generally increased, some of which can record diagnostic or personal information. Most automobiles manufactured today are equipped with (EDR) capable of storing retrievable data including vehicle speed, braking, and other parameters. More recently, cars are not the only vehicles storing data. Newer Side-by-Side (SSV) off-road vehicles and watercrafts have Engine Control Modules (ECM). These electronic devices are responsible for keeping the engine running smoothly. To complete that task, the devices monitor data from various sensors and systems. When a problem is identified, the ECM can log diagnostic fault codes. In addition to fault codes, some ECMs can record up to 60 seconds of data including vehicle speeds. Using diagnostic tools, ECM data can be retrieved to provide insight as to how fast a watercraft or SSV was traveling during the last approximate one minute of usage or its past and current diagnostic condition.

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Slippery Surface Sidelines Contractor


slip-and-fall-expert-witness

Bryan J. Smith, PE, Construction Site Safety / Slip, Trip & Fall / OSHA Expert ::::

Case Description/Summary: A painting contractor (plaintiff) was walking down an exterior home walkway after dropping off a quote for work requested by the homeowner. It just started raining, so the plaintiff decided to take a different route back to his parked car when he tripped and fell over an unguarded retaining wall. As a consequence of his trip and fall, the plaintiff sustained serious injuries. No guardrail had been present at the incident location, which could have prevented his four-foot fall. It had been dark and raining and the adjacent exterior home lighting was not turned on.

Expert Analysis: The plaintiff stated that he was walking on a flagstone walkway back to his vehicle, which was a different route from the one he used to get onto the incident property. He originally used a concrete sidewalk that bordered the large corner lot property to get to the front door of the house. Since it had started raining heavily just after he got to the porch, he decided to take the alternate flagstone side walkway as a shortcut back to his car. Just when he rounded the side of the house’s porch, he tripped over the edge of an unlighted and unguarded stone retaining wall and fell four feet to a concrete driveway below. The incident caused severe permanent injuries to the plaintiff.
The defendant’s expert argued that the property was constructed prior to the adoption of the building codes which required guardrails at every open walking surface that was 30 inches or more than adjacent lower surfaces, and hence it was “grandfathered” from compliance. He also argued that the flagstone pathway was not a “pathway” or even intended to be used as a walkway – but was in place solely for reason of erosion control of the sloped ground there.

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Following Too Closely – Not Always as Straightforward as it May Seem


Following too close

Robert T. Lynch, PE, Senior Collision Reconstruction Engineer ::::

All states have a provision within their respective Vehicle Code pertaining to “following too closely” which states, in general, that “the driver of a motor vehicle shall not follow another vehicle more closely than is reasonable and prudent, having due regard for the speed of the vehicles and the traffic upon and the condition of the highway.”(1) Whenever a rear-end impact occurs, the investigating police officer will typically list “following too closely” as a contributing factor; however, not all drivers that rear-end another vehicle are keeping an unsafe following distance (a.k.a. headway) or are following “more closely than is reasonable and prudent” having due regard for the speed of the vehicles on the highway.

Most states recommend a 3 to 4-second “following distance rule” within their driver’s manual. This rule generally provides for sufficient distance to bring a vehicle to a stop in most driving situations; however, the rule is not conducive for drivers on congested highways where keeping such a distance would allow other vehicles to “cut in line” and effectively reduce safety by increasing the number of potential vehicular conflicts. It is often argued that the following distance rule is rarely observed in practice. Support for this argument is found in the review of the attached Google Earth™ aerial image of I-95 in Philadelphia, PA which illustrates that the majority of drivers within this image are accepting a following distance of 100 feet or less, with an average time headway (assuming the vehicle are traveling at the 55-mph speed limit) of about 1 second. A headway equivalent to 1 second is consistent with published research data on “real world” typical time headways. (2) The acceptance of a reduced headway suggests that drivers are “reading the road” assessing the state of traffic as a whole and not just focusing on the vehicle directly in front of them.

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Industry Update: Latest Recommendation for Children in Child Seats


Child Seat Expert Witness

The American Academy of Pediatrics (AAP) recently published an updated policy statement regarding the transportation of children in vehicles. AAP now recommends children remain in a rear-facing car safety seat as long as possible, until they reach the highest rear-facing weight or height allowed by their child seat. Prior to this latest change, AAP recommended children should remain rear-facing until age 2. This change has resulted in confusion for parents that can be seen in social media comments and responses. These comments question if rear-facing is safer, the ability to fit a child seat for a larger child in cars, where the larger children will put their legs and when it is OK to turn a child forward facing. AAP’s recommendations are aimed at increasing the safety of children being transported and are supported by the science of occupant protection. Simply stated, we would all be safer if we could ride rear-facing, be in on a plane, train or automobile.

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