Forensic Engineers and Consultants

Archive: Pedestrian

Civil Twilight Pedestrian Collision: A Case Study

Susan, a 45-year-old runner, was jogging in the early morning approximately an hour before sunrise, also known as “civil twilight.” Civil twilight occurs both before sunrise and after sunset when the sun is below the horizon and the sky is partially illuminated. Susan was wearing dark athletic clothing and grey tennis shoes for her morning run. She was running on the sidewalk in a suburban area and began to cross the four-lane road at an unmarked crosswalk. Read More

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The Difficult Task of Avoiding Pedestrians While Driving at Night

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An alarming 6,516 pedestrians were killed, and 54,769 pedestrians were injured as a result of traffic crashes in 2020 (NHTSA, 2022). A large majority (77%) of these pedestrian fatalities occurred in low luminance conditions such as nighttime while only 20% occurred in daylight (NHTSA, 2022). This dramatic difference between pedestrian fatalities during the night and day is seen even when controlling for driver fatigue and alcohol consumption (Owens & Sivak, 1996). This phenomenon prompts the question as what is so dangerous about being a pedestrian at night? Read More

The Collision Reconstruction Matrix – The Human

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Murder, suicide, deceit, and intrigue… car crashes? You bet! In our next installment of the 9-Cell Collision Matrix let us dive a little deeper into the glue that binds all this together, the human element.

Photo by Mark Turner

Let’s begin with the most basic human element at the root cause of car wrecks, our old friend inattention. Inattention… a vast word that encompasses many lackadaisical conditions. The daydreaming 16-year-old in math class, the radio knob turner, the back seat talker, the quarter pounder with cheese eater, and perhaps the most offensive, the cell phone user. All very dangerous behind the wheel, and one very dangerous to your future… as it turns out, you will always need good math skills… ask me how I know? Driving is of course a divided attention endeavor, Read More

The Best Use of Visibility Aids – Contrast

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There are various visibility aids marketed for vulnerable road users (VRUs). Here, the term VRU is used to describe unprotected road users such as pedestrians and bicyclists. Visibility aids are designed to increase a VRU’s contrast within their environment, making them more distinguishable from the background to a driver. These visibility aids can include both active and passive ways to increase the VRU’s contrast, therefore their visibility. As the name implies, active visibility aids actively transmit light and are powered by a source (i.e., battery powered bicycle headlights and taillights) while passive visibility aids passively reflect light coming from outside sources (i.e., fluorescent, and retroreflective clothing).

There are a wide variety of active visibility aids to choose from on the market. For example, Read More

WARREN Welcomes Human Factors Consultant Ellen Szubski, Ph.D.

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Please join us in welcoming Human Factors Expert Ellen Szubski, Ph.D, to the WARREN family!

 

 

 

 

 

 

 

 

 

 

Ellen’s Areas of Expertise Include:

  • Human Factors & Safety
  • Illumination Evaluation
  • OSHA Regulations
  • Premises Liability
  • Slips, trips, and falls
  • Workplace injuries
  • Vehicle/Pedestrian/Bicycle Crash Investigation

Ellen Szubski is a human factors consultant with Warren. Her expertise focuses on the crash investigations and other personal injury matters. These matters often include collisions and/or crashes involving vulnerable road users and drivers, driver distraction, and slips, trips. & falls. She utilizers her knowledge of OSHA regulations, codes and standards in her analysis of premises liability incident and safety consulting.

Ellen graduated from Clemson University with a Master of Science in Applied Psychology and a Doctor of Philosophy in Human Factors Psychology. She did her dissertation on “The Influence of Pedestrian Biological Motion on Time-To-Collision Estimates at Night.”  Ellen is a member of the Human Factors and Ergonomic Society (HFES) and its Forensic Professional Technical Group.  She has presented multiple times at the Human Factors and Ergonomics Society Annual meetings.

The Collision Reconstruction Matrix

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It’s mid-January, the high today is 28 degrees with lows in the teens as the Carolinas are in the grip of a Canadian cold front and I’m on call tonight. The phone rings at 3:00 am; yes Sir, three cars with two fatalities, I-85 northbound, yes Sir, on the way. Despite the hurdles that lie in front of me – cold, fatigue, the loss of life – my job with the South Carolina Highway Patrol Multi-Disciplinary Accident Investigation Team (MAIT) is to investigate, document, and ultimately prosecute chargeable collisions. To properly reconstruct this collision, three essential and distinct categories must be investigated and documented in order to provide a well-founded explanation of the series of events prior to, during, and after the collision regarding the human, the vehicle, and the environment; this investigative technique is known as the 9-cell collision reconstruction matrix. Read More

WARREN Welcomes Senior Collision Reconstructionist Mark Turner, ACTAR

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Please join us in welcoming Senior Collision Reconstructionist Mark Turner, ACTAR, to the WARREN family!

Mark’s Areas of Expertise Include:

  • Tractor Trailer Accidents
  • Vehicle Collision Reconstruction
  • Crash Data Retrieval
  • Forensic Mapping Technology
  • Accident Reconstruction
  • 3D Scan Imaging and Animations

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Why investigators should have “Scaled Diagrams” of scenes?

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When it comes to diagramming a crash scene, there are several methods to accomplish the task. Forensic Mapping, (locating, positioning, and documenting the evidence of a collision scene to scale) is essential to having the answers to the questions “Who, What, Where, When, and Why?”. Photographs do a great job showing what the investigators saw post collision; yet they lack scale and the ability to describe pre-collision movement. Having a computer aided diagram (CAD) of the collision scene goes much further than the pictures can; here is why.

basic intersectionA scale diagram gives the full overview of a collision scene from either a 2D or 3D point of view. Being able to see how things lined up, how they came together and how they parted helps explain the events within a crash. When a scene can be viewed from top down or any angle, that helps relay the facts. The investigator, judge, or jury will get Read More

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