Motorcycle Accelerations while Successfully Traversing Roadway Irregularities and Traffic Calming Devices (Speed Bumps) at Small Lean Angles 2019-01-0434

There have been limited empirical studies regarding the dynamics of a motorcycle and rider as a motorcycle traverses a roadway irregularity such as a pothole or depression, or a traffic calming device (TCD) such as a speed bump. This study seeks to establish qualitative analysis of the success of motorcycles traversing various roadway irregularities/TCDs as well as quantitatively analyzing accelerations to the motorcycle at varying speeds and lean angles. Further analysis is conducted comparing the accelerations experienced in scenarios where the suspension of the motorcycle experiences extension followed by compression, as is the case when encountering a pothole or depression, as well as scenarios where the suspension of the motorcycle experiences compression followed by extension, as is the case when encountering a TCD. Largely, the study is to establish minimum values for both speeds and lean angles in which traversing roadway irregularities\TCDs of a given geometry causes little to no dynamic instability to the motorcycle and little to no discomfort to the rider. The roadway irregularities/TCDs are traversed perpendicularly and at varying lean angles. Roadway irregularities/TCDs are measured utilizing 3-dimensional (3D) laser scanning to establish the length, depth, and contour (slope) of the irregularities/TCDs. The motorcycle speeds, accelerations, and lean angles are obtained through five different on-board data logging devices. The results of this testing quantitatively and qualitatively establish that the tested motorcycle was successfully able to traverse a variety of roadway irregularities/TCDs at tested speeds up to 40 mph (64.4 kph) and lean angles less than five degrees. One test was performed at approximately 25 mph (40.2 kph) with a lean angle of 16 degrees. Further testing at higher speeds and steeper lean angles is yet to be performed.