In this article, photogrammetry expert, Steven Becker provides an introduction to some of the methods and techniques utilized by forensic experts in determining the make and model of vehicles captured…
Determining Vehicle Crush Damage from a Photograph - Advanced Crash Reconstruction Expert Article
The crash reconstruction experts at Robson Forensic are frequently asked if it’s possible to perform a meaningful crash investigation without having the damaged vehicles available for inspection. In some instances, we can. In this article, we describe how photographs can be used to determine scientifically valid vehicle crush measurements.
Advanced Crash Reconstruction - Determining Vehicle Crush Damage From a Photo
Crash investigations often occur months or years after the actual incident, and in many instances the physical evidence is no longer available for inspection. Whether the vehicles were repaired or sold for salvage, forensic investigators face the same challenge of determining scientifically accurate measurements from limited data sources.
Photogrammetry is one example of a forensic technology that can be used to yield reliable data where seemingly none exists. Photogrammetry provides a path for determining vehicle crush measurements, which can be used to deduce other important data including damage energy, Delta V, and vehicle speeds.
Calculating crush damage via photogrammetry typically requires multiple photographs of the incident vehicle(s), although other measurements can sometimes be accomplished with as few as one. From available photographs, analysts can determine the relevant 3D geometry of the incident vehicle(s). Experts can establish undamaged vehicle measurements by either applying the same approach to photos of exemplar vehicles from the same generation/make/model, or by performing scans or hand measurements of available vehicles.
Having established relevant 3D geometry for the incident and baseline vehicles, analysts can then overlay the cross-sectional outlines within a CAD (computer-aided design) environment to establish an accurate representation of crush.
In this case, our crash expert’s primary objective was to determine the speed of the vehicle that struck the side of the SUV. Our expert did not have access to either of the vehicles involved in the incident, but was able to obtain several photos from the insurance claim report that had been taken shortly after the incident.
Analyzing the available photos using the appropriate software, we were able to determine crush profiles along several different levels of the vehicle. This process yielded reliable measurements, which were combined with crush coefficients to answer the question of how fast the “bullet” vehicle was travelling at impact.
Based on the evidence available in this case, photogrammetry provided the best solution for our experts to provide a reliable and scientifically valid forensic analysis. Meaningful and accurate information can potentially be derived from photos taken by police, insurance adjusters, on cell phones, security cameras, or even PDF reports to create accurate digital models where the vehicles are no longer available for physical inspection.
Overcoming Data Gaps in Forensic Crash Investigations
Our experts are experienced in navigating online databases to determine if a crashed vehicle is still intact and if photos were taken prior to auction. Robson Forensic can sometimes help our clients locate photos, other valuable data sources, or the actual crashed vehicles. Even if there are no photos available and the vehicle’s current condition does not allow for a representative analysis, it may still be possible to recover the event data recorder and access information from the crash. Contact an expert in our technical services group to discuss the path forward in your case.
Forensic Technical Services
The technical services group at Robson Forensic provides guidance and support where advanced software, equipment, and other forensic technologies can be used to enhance the depth or accuracy of investigations. While they frequently work alongside our in-house forensic experts, the technical services group is also available for projects not involving the retention of a Robson Forensic expert.
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