Motor Vehicle Collision Case Study

This incident involved a mail truck and a package van that were involved in a motor vehicle collision. One of the questions the clients had was, did the driver of the mail truck pull out in front of the package truck or was there something else going on? How did this incident occur?

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The first part of any analysis is evaluating and reviewing and breaking down what materials and evidence you have. Part of the evidence is what we are given by the client, and so in this case, I was given a certain set of materials and then I was also provided the opportunity to do inspections. A mail truck was traveling north out of the neighborhood, and then the package van was traveling eastbound. An incident occurred a collision between the front end of the package truck and the driver's side of the mail truck. The first thing I wanted to do was investigate the rest position relative to the scene and relative to where both the package van and the mail truck were coming from. It was a four lane roadway divided by a grass median, and the rest position was actually in the right outside eastbound lane. At the time of the incident, there was actually some bushes, some foliage at the corner of the intersection that if you were in the northbound lanes pulling out of the neighborhood and you looked to your left, the foliage might cause a line of sight obstruction. Did the presence of the foliage on the corner of the intersection potentially contribute to why the mail truck may or may not have seen the package van? As he was approaching the intersection,

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I was able to go out to the scene and do some documentation of the scene. I used a FARO laser scanner, and then I also used a drone, and then I used my camera to document the layout of the scene. Then I used a tool called photogrammetry where we did camera matching in order to place both the package fan and the mail truck at their rest locations. The foliage had been cut back by the time I went to my inspection, so I was actually able to recreate the location of that based on the photos that were taken at time of the accident. And then I used photogrammetry to virtually place that foliage back into the seat. I did a series of simulations using a software program called Virtual Crash. It's a physics-based simulation software program where I build out the scene in 3D. I built the roadway from scans that I took during my site inspection, and then I had a virtual package van and a virtual mail truck that was built based on CAD models, and they were scaled to the scans that I had taken of the subject package van and the subject mail truck.

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I was able to use the physical evidence to determine how the two vehicles interacted at impact and then where they came to rest, and so by knowing that I'm able to back it up and figure out where the location of the impact occurred. What I learned was that the impact was in the right lane, and the reason why this was important is because the testimony of the package van was that he had made a lane change from the right lane to the inside lane or the left lane, but because the impact occurred in the right lane, I know that the package van breaks and swerves to the right into the mail truck. And then I also was able to determine at what speeds were the vehicles traveling. So I had a range of speeds for both the mail truck and the package van based on the vehicle damage and the rest positions.

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What I was able to determine is that if a northbound vehicle, if that driver had looked to his left, there was a line of side obstruction so that as the mail truck starts to proceed forward, the package van is not in his light of sight. And if that was true based on the testimony, then the package van had to be going in excess of the speed limit at the time of the incident. The evidence also indicated to me that the package van hit his brakes prior to impact, so he did try to avoid and he did swerve to the right, but in swerving to the right, he actually swerved into the impact, and if he had just maintained his lane of travel, he would've just driven right past the mail truck.

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