Expert Witness

Sliding and Tumbling Deceleration of a Motorcycle (Motorcycle Accident Reconstruction)

Sliding and Tumbling Deceleration of a Motorcycle (Motorcycle Accident Reconstruction)

A quick aside...this is a draft of another section from the motorcycle accident reconstruction book that I'm writing with Lou Peck and William Neale. Lou, in particular, assisted with this section. Let me know what suggestions you have for making this more readable and useful. Thanks!

Producing Forensic Animations that are Credible and Admissible (Motorcycle Crash Example)

Producing Forensic Animations that are Credible and Admissible (Motorcycle Crash Example)

An animation can provide tremendous value to a jury by making an expert’s opinions more understandable. In this article, I will give you 7 principles for producing credible and admissible animations for use in depositions, mediations, settlement conferences, and trials.

Forensic Acquisition of Vehicle Infotainment Systems Data

Forensic Acquisition of Vehicle Infotainment Systems Data

Hey, everybody. In this article I’m passing along a conversation I recently had with Will Bortles of Kineticorp about the research he just published at the 2017 Society of Automotive Engineers World Congress. This research relates to methods for acquiring data from passenger vehicle infotainment systems.

Simulating Rollovers in PC-Crash

Simulating Rollovers in PC-Crash

If you missed Parts I or II of this series, here are links to those: Part I and Part II. In this installment, I review the prior literature related to using PC-Crash software to simulate rollover crashes. In a future installment, I will extend this prior literature and present analysis of a full-scale, steering-induced rollover crash test with PC-Crash.

Part II - An Analytical Review of Two Decades of Research Related to PC-Crash Simulation Software

Part II - An Analytical Review of Two Decades of Research Related to PC-Crash Simulation Software

Studies Describing the Conceptual Models: The PC-Crash technical manual describes the theoretical models utilized by the software, and users should consult that manual for information related to the latest versions of the models.

An Analytical Review of Two Decades of Research Related to PC-Crash Simulation Software - Part I

An Analytical Review of Two Decades of Research Related to PC-Crash Simulation Software - Part I

PC-Crash is a vehicular accident simulation software that is widely used in the accident reconstruction community. Later parts of this article will review the prior literature that has addressed the capabilities of PC-Crash along with its accuracy and reliability for various applications (planar collisions, rollovers, and human motion). I actively use PC-Crash software in my accident reconstruction practice.

Fracture Energy Calculations for Wooden Utility Poles (Accident Reconstruction)

Fracture Energy Calculations for Wooden Utility Poles (Accident Reconstruction)

The following mechanisms of energy dissipation may need to be considered when calculating the initial speed of a vehicle that impacted a wooden utility pole: (1) crushing of the vehicle; (2) full or partial fracture of the pole; (3) moving and tilting of the pole within the ground; (4) acceleration of the pole after a full fracture; and (5) tire, and other dragging forces, acting on the vehicle during its post-impact motion [Daily, 2009; Cofone, 2007 and 2012]. 

Use Physics and Evidence to Test what Witnesses Say About a Crash

Use Physics and Evidence to Test what Witnesses Say About a Crash

When we are analyzing a crash, how should we as accident reconstructionists approach what eyewitnesses and involved drivers say about what happened? For some reason, I feel obligated to say the obvious - yes, witnesses are poor estimators of speed and distance. We all know that. But today, I want to encourage you not to use that as an excuse to dismiss everything that a witness says.