Category : Uncategorized

The Need for Speed: Obtaining Speed From Video

James R. Schmidt, Jr., BSME, Collision Reconstruction Engineering Analyst

You guessed it! If Jim Schmidt is writing something, it must be regarding speed from video! That’s because I’m passionate about what I do! They don’t call me “Captain Video” for nothing.

A new year. A new dash cam. A routine drive home in the evening. One thing leads to another, pushpins were plotted, speed was calculated, and wouldn’t you know it … the same results! Perfection!

Pushpins were plotted for 59 seconds and 0.6 miles of travel. A speed versus time profile was generated from this plotting, and a comparison was made with the GPS speeds shown on the dash cam display. Assuming for this example the GPS speed display to be the actual speed of the vehicle (which is a reasonable assumption for normal driving with gradual speed variations), the independently calculated speeds were within 2 mph of actual over this entire time and distance. Additional pushpins could be plotted to refine this even further.

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Stop Sign Obstruction: Was it the Cause of a Motorcycle Collision?


Justin P. Schorr, Ph.D., Principal Collision Reconstruction Engineer

Synopsis: A motorcycle was traveling southbound on a two-lane, two-direction roadway approaching a T-type intersection with a four-lane roadway. The motorcycle operator (plaintiff) failed to stop at the posted stop sign and entered the four-lane roadway where he was involved in a collision with a westbound vehicle.

The motorcycle operator testified he was traveling at the posted speed limit of 35 mph as he approached the intersection but, due to the stop sign being obstructed, perceived the traffic control at the last instant and did not have sufficient time and distance to stop prior to entering the four-lane roadway.

The plaintiff contended that tree branches obstructed the stop sign and therefore sued the State [the governing authority for the roadway], as well as the owner of the property on which the tree was located. The area of the collision was reportedly changed by the time suit was filed. The plaintiff provided no specific “hard copy” data, including photographs or measurements, to establish the obstruction or the extent of the obstruction.

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Heads-Up Displays: Aiding or Obstructing?


Laurence R. Penn, Senior Forensic Animation / Video Specialist
Justin P. Schorr, Ph.D., Principal Collision Reconstruction Engineer

The CES annual tradeshow (organized by the Consumer Technology Association) has been touted as the most influential tech event in the world – the place where revolutionary consumer technology is announced and displayed to the public. Since the first show took place in 1967, many products that seem old or nostalgic to us now were considered the highest of high-tech at the time when they were first announced. Such products included VCRs (1970), CDs (1981), HDTVs (1998), and drones (2015).

At the most recent CES show, which occurred virtually mid-January 2021, the newest technologies included vehicle heads-up displays or HUDs. With advances in miniaturizing and optimizing real-time 3D LIDAR scanning, their presence in new vehicles is becoming more and more prevalent. Combining real-time object collision detection and digital display technology, data can be displayed on dashboards or windshield to make drivers more aware of their surroundings or provide entertainment while the vehicle is in self-driving autonomous mode. In the demo videos of this new technology, “on-screen” alerts as well as visual cues are aligned with the actual position of a potential obstacle or hazard.

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Setting Boundaries: Construction Work Zone

construction code expert witness

Lt. Col. Bryan Smith, P.E., Construction Site Safety Consultant

Case Summary: A dump truck, which exited a construction zone after delivering a load of asphalt paving material, struck and killed a pedestrian. The construction firm that performed the parking lot repairs hired an expert to evaluate the incident location and determine if it was within a work zone and if so, whether certain motor vehicle/pedestrian precautions were necessary and/or enacted by the construction firm.

Expert Analysis: An evaluation of the incident location was made using Google Earth satellite photos. The Google Earth photos documented what work had been performed at the time of the incident, about one year and nine months earlier from the engagement of an expert.

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Pennsylvania State Law: Stopped Emergency Vehicles – Move Over or Slow Your Roll

Trucking and Transportation Expert

Timothy P. Reilly, P.E., Civil Engineer

Most motorists will have seen these signs on Pennsylvania roads and are familiar with their duty to move into an adjacent lane to give more room to emergency vehicles stopped on the side of the road. This helps to protect emergency service responders in a vulnerable position along an active highway and reduces the risk for subsequent collisions with emergency vehicles or the vehicles to which they are responding. As noted in the Pennsylvania Vehicle Code, Emergency Service Responders include police officers; firefighters; EMS and ambulance personnel; towing and recovery workers; and highway maintenance and construction personnel.

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OSHA Multi Employer

Walter M. Wysowaty, PE, CME, Civil Engineering Consultant

Case Facts: The plaintiff was employed by an environmental consultant who was responsible for work related to the removal of underground storage tanks (UST), including the collection of soil to be tested for contamination. A contractor qualified for excavations associated with UST’s performed soil excavation to remove the tank to a depth of somewhere between 7 and 10 feet. The resultant soil wall was generally vertical with some undermining that existed after removal of the tank. Shoring at the excavation was not installed. The plaintiff testified that he did not feel that excavation was safe, yet approached the top elevation of the excavation to collect various data. While standing at the top elevation, the soil wall failed resulting in injuries to the plaintiff. The plaintiff had received OSHA training prior to the subject incident.

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