Motorcycle accident expert Dr. John Lloyd has served attorneys nationwide for 25+ years in biomechanics, human factors, helmet testing and motorcycle accident expert
Motorcycles are considerably more complex to operate than cars, and riders are significantly more vulnerable to potentially devastating injuries. Motorcycle crashes may be caused by a number of factors, including rider error or inexperience, excessive speed, other driver distraction, carelessness or inattention, roadway or mechanical defects, and weather related hazards. For these reasons, a motorcycle crash expert is critically important in a motorcycle crash case.
Dr. Lloyd’s interest in motorcycling began at the age of 13, when he built his first motorcycle and learned to ride. Since that time he has amassed many years of technical expertise. In addition to holding a PhD in Ergonomics (Human Factors), with a specialization in Biomechanics, John holds several certifications in motorcycle accident reconstruction.
Based on his 38+ years of riding and advanced training as a motorcyclist, he is one of a few experts who have been admitted in court to testify regarding motorcycle handling and operation.
Using his FAA part 109 pilot’s license, Dr. Lloyd can fly drones to generate 3D forensic maps of crash scenes for reconstruction purposes. Based on his PhD in human factors / ergonomics, John is qualified to address human factors issues including line of sight analysis, perception response time (PRT), distracted driving and impairment. Given his extensive experience as a senior researcher in biomechanics, with a specialization in head and brain injury biomechanics, including research and development of helmets, Dr. Lloyd is also uniquely qualified to opine on injury biomechanics and motorcycle helmet protection issues.
Links to several of Dr. Lloyd’s articles pertaining to motorcycle accident reconstruction and biomechanical evaluation of motorcycle helmets are presented below:
Dr. John Lloyd has over 30 years of forensic consulting experience as a motorcycle accident expert including motorcycle handling and operation as well as maintenance, repair and motorcycle inspection.
The number one cause of motorcycle crashes involving other vehicles is a left-turning driver across the rider’s path. In every case, the intruding motorist explains that they “did not see the approaching motorcycle”. The motorcycle was not conspicuous.
Expectancy
How can a motorist fail to see something as large as a modern motorcycle? The answer – expectancy. According to the National Highway Transportation Safety Authority (NHTSA), motorcycles account for only 0.6% of total vehicle miles traveled in the United States. Thus, motorists have more than a 99% expectancy that the next vehicle they see will NOT be a motorcycle. Through experiential learning drivers have learned to look for other automobiles, not motorcycles.
It is not that a motorist does not see the motorcycle. However, it does not meet their expectation and therefore they may fail to identify the approaching motorcycle.
What can motorcyclists do to reduce their risk of collision when a driver causes a path obstruction at an intersection? According to human factors research, roadway users respond to hazards based on available information. They fail to respond when the available information is insufficient. Based on my experience as a motorcycle rider and human factor expert, conspicuity is key to increasing the information available to motorists. As motorcyclists we need to take responsibility to make our presence known to other roadway users.
Many opportunities to improve conspicuity are available, which generally fall into two categories – audible and visual. Many riders are familiar with the concept “Loud pipes save lives”, as often declared on stickers affixed to their helmets. However, since noise intensity decreases as a function of the distance-squared, loud pipes are only effective in close proximity. Moreover, the greater volume is actually behind the motorcycle, not in front.
Human Factors research teaches that to improve driver detection and therefore avoidance of motorcycles on the road, we can enhance our visual conspicuity by following a few simple guidelines. These are captured by the acronym CAPLETS, which includes Contrast, Anticipation, Pattern, Lighting, Eccentricity, Time of Exposure, and Size.
Conspicuous Contrast
Contrast addresses the ability of a motorcycle and rider to stand out from their environment. For example, a black motorcycle on an asphalt surface is more difficult to distinguish than a yellow or red bike, especially under nighttime conditions. The same is true for the rider. Dark clothing makes it more difficult for a motorcyclist to be detected on the roadway. Brighter colors, especially high-vis yellow or orange, are more likely to create a greater contrast and therefore be more recognizable.
Anticipation Conspicuity
Anticipation refers to the expectation of a given event. When motorcyclists ride together in a group, motorists are more likely to expect and therefore look for additional motorcycles. For this reason, a group riding together is often safer than a solo motorcyclist traveling alone.
Conspicuous Patterns
Patterns aid recognition by relying on one’s past experiences. Obviously, most motorists are familiar with the shape or pattern of a motorcycle and can easily distinguish one during daytime conditions. However, at night the pattern exhibited by a single headlight, may not aid a driver in identifying an approaching motorcycle. Motorcycles equipped with additional lighting that outlines its shape are more likely to be recognized on the roadway and hence less likely that their path will be intruded by a motorist.
Conspicuous Lighting
The purpose of Lighting is somewhat self-explanatory. More lighting means more information for other roadway users. Lighting is beneficial not just at night, but also during the day. The photograph, below, of one of my motorcycles illustrates how effective additional lighting is in providing information necessary to motorists to recognize my presence on a motorcycle. Headlight modulators can also increase conspicuity by switching between low and high beam automatically at a rate of approximately 4 times per second. The modulators are equipped with a light sensor, which turns off this feature at night. I have personally installed headlight modulators on several of my bikes and can attest as to their effectiveness.
Eccentricity
Eccentricity relates to the viewing angle. When a motorcycle is approaching an intersection, the viewing angle of the rider to an automobile on the right, waiting to make a left turn across the roadway is close to zero. Whereas, for the driver at the road junction, their viewing angle, unless properly turning their head to look for oncoming vehicles, is close to 90 degrees. There is not much that a rider can do to improve the motorists viewing angle. However, I have found that, when approaching an intersection at which a driver is waiting to make a turn across my path, by moving my motorcycle side to side within my lane helps to catch their attention.
Time of Exposure
Time of Exposure. It is critically important at intersections to ensure that no visual obstructions exist between the rider and motorist that could limit time available to detect your presence. If fixed obstructions, such as trees or signage, are present I will position my motorcycle in a manner that provides a clear line of sight. Whereas, if a vehicle in front of or to the right of my motorcycle may pose a potential visual obstruction at an approaching intersection, I will move forward, or drop back, allowing a clear 3-second window between myself and other vehicles, thereby affording a waiting motorist every opportunity to detect and identify me on the road. Speed can also negatively affect time of exposure. At greater speeds other drivers have less available time to detect a motorcyclists presence. For this reason, I advise that it is best to travel at or within 5 mph of the posted speed limit.
Conspicuous Size
Size matters, when it comes to conspicuity. Remember that motorists are looking for other automobiles. Larger motorcycles tend to be identified more quickly than smaller bikes, or bicycles. An opportunity may exist to make your motorcycle appear larger than reality through the use of additional lighting, such as led lights mounted on left and right side mirrors, and/or by the front wheel axle.
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.
Motorcycle collision analysis is a highly specialized discipline in which Dr. Lloyd is eminently qualified as a motorcycle accident expert. In addition to holding a PhD in Ergonomics (Human Factors), with a specialization in Biomechanics, John has more that 20 years and 200,000 miles of experience riding motorcycles. Dr. Lloyd has completed numerous advanced programs, including Motorcycle Safety Foundation (MSF), Experienced Rider Course and Total Rider Tech Advanced training.
Motorcycle Helmets and Brain Injury
To consider whether a motorcycle helmet might reduce the risk of brain trauma in a motorcycle accident it is first important to understand the two primary mechanisms associated with traumatic brain injury – impact loading and impulse loading.
Impact loading involves a direct blow transmitted primarily through the center of mass of the head, resulting in extracranial focal injuries, such as contusions, lacerations and external hematomas, as well as skull fractures. Shock waves from blunt force trauma may also cause underlying focal brain injuries, such as cerebral contusions, subarachnoid hematomas and intracerebral hemorrhages. Whereas, impulse or inertial loading caused by sudden movement of the brain relative to the skull, produces cerebral concussion. Inertial loading at the surface of the brain can cause subdural hemorrhage due to bridging vein rupture, whereas if affecting the neural structures deeper within the brain can produce diffuse axonal injury (DAI).
Holbourn was the first to cite angular / rotational acceleration as an important mechanism in brain injury. Gennarelli, Thibault, and colleagues, in a series of studies using live primates and physical models investigated the role of rotational acceleration in brain injury. They concluded that angular acceleration contributes more than linear acceleration to brain injuries, including concussion, axonal injury, and subdural hematoma.
Motorcycle Helmet Testing
Traditional testing of motorcycle helmets focuses on reducing the effect of linear impact forces by dropping them from a given height onto an anvil and measuring the resultant peak linear acceleration. According to the Federal Motor Vehicle Safety Standard (FMVSS) 218, commonly known as the DOT helmet standard, the test involves dropping a motorcycle helmet onto a flat steel and hemispherical anvil at an impact velocity of 6.0 m/s (13.4mph). In general, if peak linear acceleration is less than 400g, the helmet is considered acceptable. Current motorcycle helmet testing standards do not incorporate measures of angular acceleration and therefore do not address whether any helmets can provide adequate protection against catastrophic brain injuries, such as concussion, axonal injury and subdural hematoma.
In 1995, the European Commission Directorate General for Energy and Transport initiated a Cooperative Scientific and Technical Research (COST) program to investigate Motorcycle Safety Helmets. Several agencies from Finland, the United Kingdom, France and Germany participated in this study, which compiled and analyzed data from 4,700 motorcycle fatalities in Europe, each year. The COST report documents that 75% of all fatal motorcycle accidents involve head injury. Linear forces were present in only 31% of fatal head injuries, while rotational forces were found to be the primary cause in over 60% of cases. Within the scope of this study experiments were performed using drop tests with accelerometers to measure linear and rotational accelerations of the brain and skull mass associated with different types of impacts. These tests confirmed rotational acceleration to be a primary cause of brain injury in helmeted motorcycle accidents.
Rotational forces acting on the brain are the underlying cause of traumatic brain injuries.
Motorcycle helmets, including those certified under DOT and SNELL standards are designed to mitigate forces associated with linear acceleration.
Motorcycle helmets are not currently certified under either DOT or SNELL standard against their ability to protect against the angular / rotational forces.
Epidemiologic evidence from the COST-327 report indicates that motorcycle helmets do not provide adequate protection against closed head and brain injuries
Human Factors of Motorcycle Accidents
Human factors in vehicle collisions include all factors related to drivers and other road users that may contribute to a collision. Examples include driver behavior, visual and auditory acuity, decision-making ability, and reaction speed. A 1985 report based on British and American crash data found driver error, intoxication and other human factors contribute wholly or partly to about 93% of crashes.
Motorcycle Inspection
Motorcycle accident analysis often requires involves a teardown and careful inspection of the machine to investigate for possible contributing factors. Our engineers have a combined 70 years experience with motorcycle mechanics.
A thorough evaluation includes inspection of tires, brakes, suspension setup, electrical components as well as any aftermarket parts.
Dr. Lloyd has completed numerous advanced programs, including Motorcycle Safety Foundation (MSF), Experienced Rider Course and Total Rider Tech Advanced training.
