Tag Archives: accident expert

Crash Scene Inspection

Analyzing a crash scene may be somewhat complex, but can be critical to understanding the nature of the collision. Some of the questions I, as an experienced motorcyclist, consider when performing a crash scene inspection include: What was the general condition of the roadway at the time of the crash? Are there any hazards, such as potholes, gouges, debris, uneven lanes, tar snakes, cattle grids, etc., that could have affected the stability of a motorcycle? Did the topography of the roadway cause or contribute to the collision? Did fluid residue on the road surface affect braking efficiency? Were there any unexpected hazards, such as a hidden driveway? Did roadway design play a factor, such as traffic signals on a curve or below the crest of a hill? Many of these questions, and more, are best addressed through an in-person crash scene inspection.

drag sled braker box

Coefficient of Friction, or drag factor, of the roadway at the scene of the crash is an important measurement, but one that is rarely completed by law enforcement traffic investigators. Fluids, such as engine and transmission oils from poorly maintained vehicles, often accumulate at or near intersections, especially those with traffic signals.
This residue can reduce motorcycle braking efficiency by 50 percent, or more, especially when wet. The Drag Factor can be easily measured using a simple, but effective tool, known as a Braker Box.

drone

Dr. Lloyd, has obtained his FAA part 109 unmanned aircraft systems pilot license. As part of his crash scene inspection he will fly a drone to capture aerial images and videos at the crash scene. Sometimes, if the crash scene is in the vicinity of an airport, special authorization may be required from the FAA.

By flying a grid mission, as illustrated below, an array of aerial images are captured. A ‘point cloud’ is created using specialized photogrammetry software, to produce a high resolution 3D model of the crash scene.

photogrammetry
3D crash scene map

Please call Dr. Lloyd at 813-624-8986 or email DrJohnLloyd@Tampabay.RR.com to discuss how he can be of help to you with your case.

Accident Reconstruction

In the United States there are 11 million motor vehicle accidents each year, more than 400,000 of which result in death. The most common injuries resulting from automobile accidents are to the head, brain, neck, and low back. The evaluation of such cases often involves a team of experts, including accident reconstruction, biomechanics and human factors experts.

As an expert witness in biomechanics and human factors as well as a certified accident reconstructionist for motorcycle crashes, automobile accident, and truck collisions, r. John Lloyd is a highly qualified testifying expert witness.

accident reconstruction expert Dr. John Lloyd

Accident Reconstruction

First the accident reconstructionist evaluates the physical evidence from a crash scene, including skid marks, gouges and other roadway markings, along with crush information from the vehicles along with their final rest positions. This evidence is used to calculate the change in velocity of the subject vehicles. 

Biomechanical Analysis

lloyd accident reconstruction biomechanica modelingThe complete anatomy of the crash (pre and post impact vehicle speeds, whether or not seat belts were worn, faulty airbags, etc.) is conveyed to the biomechanics expert.

Biomechanists use this information to determine occupant kinematics (motion of the vehicle occupants in response to the impact), kinetics (forces acting on various body parts as a result of the collision) and injury mechanisms. This can include the impact to the head and forces transmitted to the brain, blunt trauma to the low back, and shear forces to the cervical vertebrae. Findings are used to determine whether impact locations and forces provide a causal explanation for claimed injuries. Hence the biomechanist can provide rationale as to whom was at fault for the sustained injuries.

As an expert witness in biomechanics and human factors as well as a certified accident reconstructionist for motorcycle crashes, automobile accidents, truck collisions, in addition to bicycle and pedestrian accidents, Dr. John Lloyd is highly valued expert for the evaluation of motor vehicle crashes.

Call Dr. Lloyd at 813-624-8986 or email DrJohnLloyd@Tampabay.RR.com to discuss how he can be of help to you with your case.