Category Archives: motorcycle accident analysis

Motorcycle accident analysis Dr. John Lloyd has served attorneys nationwide for 25+ years in biomechanics, human factors, helmet testing and motorcycle 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.

motorcycle road hazard - tar snakes
tar snakes
motorcycle road hazard - gouges
roadway gouges
motorcycle road hazard - pothole
potholes
motorcycle road hazard - cattle grid
cattle grid
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.

Research Article “Biomechanics of Motorcycle Accidents” published in Journal of Forensic Biomechanics

Dr. John Lloyd is pleased to announce that his latest research on Motorcycle Accident Biomechanics was published in the Journal of Forensic Biomechanics on January 25th, 2016.

motorcycle accident biomechanics - Dr John Lloyd

Abstract:

Motorcycles are a luxury in the developed world, where they are used mostly for recreation. Whereas in developing countries, motorcycles are required for utilitarian purposes due to lower prices and greater fuel economy. It is estimated that in 2016 there will be more than 134 million motorcycles worldwide, 60-80% of which are in the Asia Pacific and Southern and Eastern Asia regions. In 2011 there were more than 8.2 million registered motorcycles in the United States, representing 3% of all US registered vehicles, with California, Florida and Texas leading the number of motorcycles per state.

In the United States motorcyclists travelled 18.5 billion miles in 2011, which represents only 0.6% of total vehicle miles travelled, yet motorcyclists accounted for 14% (4,612) of traffic fatalities and 4% (81,000) of all occupant injuries 2. According to the U.S. National Highway Traffic Safety Administration (NHTSA), when compared with automobiles, per vehicle mile traveled, motorcyclists’ risk of a fatal crash is 35 times greater than that of a car occupant

In a motorcycle accident, the motorcycle and rider typically become independent, each following their own path to final rest. Consequently, the biomechanical analysis of a motorcycle accident is complex. A biomechanical model to assess rider kinematics associated with motorcycle accidents is presented, which may be important to forensic scientists involved in the analysis of such events. This model can also be applied to other activities, including cycling, equestrian sports, skiing, skating, running, etc.

It is first important to understand the mechanisms by which a rider may be ejected from their motorcycle and how drag factors affect the motorcycle and rider independently. Next we determine rider trajectory, taking into consideration rider anthropometry and posture, results from which are used to derive impact velocity as a function of linear and angular components. A case study is presented, demonstrating how the presented model can be applied to a collision involving a single motorcycle.