ATA'S "THE EXPERT" NEWSLETTER - ISSUE OF AUGUST 2019




In this Issue:

Reconstructing a High-Speed Motorcycle Crash

Drone Generated Imagery in 3D Animation

ATA Uses Software to Enhance Usage of Surveillance Video

This Issue's Toolbox Feature - Boating/Marine

































RECONSTRUCTING A HIGH-SPEED MOTORCYCLE CRASH



ATA experts recently played a vital role in the successful defense at trial of a major oil company in a lawsuit related to a horrific, pre-dawn, fatal crash between a motorcycle and a semi tanker. The case was unusual in the variety of different forensic techniques that ATA needed to use to reconstruct the accident and to address a persistent, unlikely claim by the plaintiff. The key mitigating fact that had to be established in defense of the tanker’s driver was an unreasonably high approach speed by the motorcycle as the tanker turned onto a rural Oklahoma highway.

A global positioning system (GPS) record from the semi-tractor documented the semi tanker’s turn onto the highway from a roadside stop sign and the tractor’s progress to its post-accident final stop position. However, that GPS record required significant interpretation and augmentation before it could be used as a reconstruction input, because (as was detailed in the previous issue of this newsletter) the path of a tractor-mounted GPS antenna is not the same as the path of the semi-trailer following behind it, and it was the trailer that was struck by the motorcycle and rider in this accident. Unfortunately, there was no electronic record of any kind from the motorcycle, so its path and speed had to be determined by other means from other evidence.

The initial most striking aspect of photos captured at the accident scene by first responders was the degree of fragmentation of the motorcycle and the wide dispersal of the wreckage fragments. This was the first indicator to ATA’s experts of a high speed impact, although there was no reliable, direct means for quantifying the impact speed from the character and extent of the debris field. It would be a signature feature of the case that, in spite of abundant evidence to the contrary, the plaintiff would continue to insist that the motorcycle’s impact speed with the trailer had been modest.


Damage to the trailer clearly showed that the motorcycle and rider had each made separate, discrete impacts with the trailer: the rider, striking high on the trailer first, and then the motorcycle, lower down an instant later. ATA used data from a published study of motorcycle impacts into a barrier with a size and mass similar to the subject trailer to calculate the speeds needed for impacts by the rider alone and the motorcycle alone to produce a lateral skid of the trailer’s tires. This speed range, from 86 to 113 mph, suggested the likely range of the upper limit on the motorcycle’s post-braking impact speed, since there was no evidence of any lateral skidding by the trailer at the accident site.


Line of sight along the highway was another significant issue in understanding this accident. The elevation profile of the highway obscured the approaching motorcycle from the tanker driver’s view until the motorcycle was about a half mile away from the stop sign at the intersection where the collision occurred. The practical effect of that line of sight limit on the driver’s perception of the motorcycle’s proximity was demonstrated for the jury by videos, recorded at night, of an exemplar motorcycle approaching the intersection at test speeds ranging from the local speed limit of 65 mph up to 110 mph.


Finally, to address the plaintiff’s dubious claim that damage to the motorcycle was primarily the result of being run over by the trailer rather than from impacting the trailer, about 50 pieces of the motorcycle were re-assembled and wired together like dinosaur bones in a museum. The resulting demonstrative aid showed little evidence of being crushed or dragged under the trailer, but appeared instead as though it had shattered explosively after being dropped from some great height.



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DRONE GENERATED IMAGERY USED IN ANIMATION




The staff at ATA are in the process of integrating the use of drone technology as part of our investigative process. One exciting way UAVs (Unmanned Aerial Vehicles) can be utilized is in creating highly accurate and visually appealing site environments for forensic 3D animations.



ATA recently worked a case in which two watercraft were involved in a collision in a south Louisiana bayou. They approached each other traveling through a snaking waterway which left each blind to the other boat. To show each of their paths to the point of collision, we used imagery derived from a drone making a photogrammetric aerial survey of the accident site.


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ATA USES SOFTWARE TO ENHANCE USAGE OF SURVEILLANCE VIDEO




In many cases, store video cameras are used but do not show enough angles to make your case. Obtaining precise distances, locations of where people or vehicles are located, or recreating an accurate 3-D site can be difficult. ATA Associates, using court qualified software program Input-Ace, has the capability to take raw video camera footage and obtain accurate information.

After inputting the video camera footage and a site 3-D scan image into Input-Ace, the software corrects the lens distortion from the camera. After the lens distortion is corrected, the video can now be overlaid with the 3-D image creating a live view of the video on top of the 3-D image. The live view can be matched with our 3-D software program where we can use the live footage to detect where certain objects are that are no longer at the actual site.



For example, ATA Associates had a case where a group of teenagers had a confrontation with an older male in a convenience store. They went outside of the store where shots were fired from both sides. The attorneys wanted to know who fired first. One side claimed that one of the teenagers fired first, while the opposite side claimed the off screen older male fired first. We were able to show the older male fired first, due to the fact the first shot could not have come from the direction of the teenagers.


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This issue’s featured topic for ATA’s Toolbox is Boating and Marine. Over 45 years ago, ATA’s original focus was on investigating boating and marine incidents, as well as studying boating safety issues. We have been involved with advanced level water craft testing and have been working maritime/shipping cases for decades

For more information on this critical topic, visit the ATA Toolbox/Marine drawer.


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