I just made a proposal to SAE for a new course titled “Applying Automotive EDR Data to Motorcycle Accident Reconstruction.” Here are some of the specifics, which I would love your thoughts on. What would improve this concept? What would make this course more useful. I’ll be offering this course for the first time on November 6, 2019 in Denver, along with Alan Moore’s class “Accident Reconstruction, the Automomous Vehicle and ADAS” (November 5) and Neal Carter’s new class on using drones for mapping accident sites (November 7). Hold these dates if you are interested…more info to come.
With the three-wheeled motorcycles in this study, the average decelerations for the tests that utilized both the front and rear brakes varied between 0.74 and 0.91 g. This range is situated in the upper half of the corresponding range for two-wheeled motorcycles (0.54 to 0.96 g). This is consistent with the fact that two-wheeled motorcycles require more skill for braking since there is more of a risk of capsizing if the rider locks up a wheel, particularly the front. For the three-wheeled motorcycles, less skill is required since the risk of capsizing is minimal, and the rider can lock up the wheels.
I’m in the midst of preparing 2 articles and a presentation for the upcoming EDR Summit in Houston (March 4-6, 2019). My topic is the use of struck vehicle EDR-data when reconstruction motorcycle-versus-passenger vehcile collisions. I thought I would put a teaser on the topic out into the world and also, hopefully, pass along some useful information. I’d love your thoughts on this topic. Read this post and then reach out to me at email@example.com or leave comments on the post. Thanks and I’ll see you in Houston!
This article describes the reconstruction of an intersection collision involving a motorcycle. EDR data from the sport utility vehicle that was struck by the motorcycle is incorporated into the reconstruction. This collision involved a motorcyclist riding a 2007 Harley-Davidson FLSTFI Fat Boy eastbound through the subject intersection. The driver of a westbound 2010 Ford Edge attempted to turn left to go southbound and the motorcycle struck the passenger’s side rear of the Ford. The driver of the Ford stated that she did not see the motorcycle prior to initiating her turn on a yellow traffic signal. A witness who observed the motorcycle prior to the collision stated that the motorcyclist accelerated into the intersection to make it through on the yellow light. The speed limit for east-west traffic through the intersection was 60 mph. An investigating officer noted that sun glare could have been a factor contributing to the Ford driver not seeing the motorcyclist.
In 1977, Hurt noted that “the most likely comment of an automobile driver involved in a traffic collision with a motorcycle is that he, or she, did not SEE the motorcycle…” Hurt continued: “The origin of this problem seems to be related to the element of conspicuity (or conspicuousness) of the motorcycle; in other words, how easy it is to see the motorcycle. When the motorcycle and the automobile are on collision paths, or when the vehicles are in opposing traffic, the conspicuity due to motion is very low, if it exists at all. Consequently, recognition of the motorcycle by the automobile driver will depend entirely upon the conspicuity due to contrast. If the approaching motorcycle and rider blend well with the background scene, and if the automobile driver has not developed improved visual search habits which include low-threat targets…the motorcycle will not be recognized as a vehicle and a traffic hazard exists” (emphasis added). But there is more to the story than that.
At times, an estimate of the center of gravity height of a motorcycle may be needed. For example, for a motorcycle crash that occurs on a curve, the center of gravity height may come into the calculation of the lean angle required for the motorcycle to follow a specific path through a curve. This analysis may play a role in determining why the motorcyclist crashed [Rose, 2014]. Cossalter  presented equations for calculating the required lean angle of a motorcycle for a particular curve that take into account the width of the motorcycle tires. Carter  and Rose  validated Cossalter’s equations. These equations utilize an estimate of the combined center of gravity height of the motorcycle and rider, an estimate that will first require an estimate of the center of gravity height of the motorcycle without the rider. Foale  has presented a method for calculating a combined motorcycle/rider center of gravity height once the center of gravity height of the motorcycle is known.
YouTube is a treasure trove of real-world crash data that is advancing the science of accident reconstruction. Take the videos posted by Ken Snyder (aka RNickeymouse), for instance. On the weekends, you may find Snyder among those perched at Edwards Corner with a camera. This 180-degree curve is the final curve on a section of the Mulholland Highway motorcyclists often call the Snake (the photograph below shows this curve).