Comfort and controllability of bicycles as a function of rumble strip design

This research examines the fundamental relationships between rumble strip dimensions, bicyclists' perceptions of ride comfort, and the controllability of a bicycle and investigates the causes of discomfort as well as controllability problems that bicyclists experience while traversing rumble strips. These goals are fulfilled by using data gathered during a recent project, the Bicycle-Tolerable Shoulder Rumble Strips project (Elefteriadou et al. 2000), conducted at the Pennsylvania Transportation Institute (PTI), and by gathering supplemental data to evaluate the ride quality of bicycles. The primary objectives are: (1) To investigate the relationship between whole-body vibration generated by milled rumble strips and bicyclists' perceptions of comfort. (2) To investigate the relationship between whole-body vibration generated by milled rumble strips and the controllability of a bicycle. (3) To identify the conditions that cause bicyclists to experience the highest levels of discomfort and control problems while traversing milled rumble strips.; The bicycle tests of the Bicycle-Tolerable Rumble Strips project involved collection of comfort and control data as volunteer bicyclists traversed six milled rumble strip configurations. The volunteer participants rode different types of bicycles over the rumble strip configurations at different speeds. Vertical and pitch angular accelerations were collected while the bicyclists traversed the different configurations. In addition, bicyclists' perceptions were recorded through a subjective questionnaire rating the comfort and controllability of the configurations. The controllability of a bicycle was also assess by calculating the percentage of time the front bicycle tire deviated laterally from a 203 mm wide line painted down the middle of the rumble strips. These data, along with background information on the participants, were input into a master database that was utilized to fulfill the objectives of this research.; A methodology is developed for quantifying whole-body vibration experienced by bicyclists. The effects of two complex motions are integrated into one measure to assess the effect on comfort and controllability.; The relationships between whole-body vibration and bicyclists' perceptions of comfort and the controllability of bicycles are assessed from several statistical models.; Several linear regression models are developed to explain how whole-body vibration varies depending upon the dimensions of rumble strips, the characteristics of the bicycle, and the characteristics of the bicyclist. By modeling whole-body vibration and by understanding the relationships between whole-body vibration, comfort, and controllability, the conditions (rumble strip design elements, bicycle type, speed, etc.) that cause bicyclists to experience the highest levels of discomfort and control problems while traversing milled rumble strips are identified.; The ride characteristics of the bicycles used during the Bicycle-Tolerable Shoulder Rumble Strips project are also assessed. (Abstract shortened by UMI.)...