Comparison of Speed Control Bumps and Humps according to Whole-Body Vibration Exposure

One of the easiest and most efficient ways to control vehicle speeds is to create undulations perpendicular to the axis of the road. The types of undulations especially used for speed management on urban road networks are called speed control bumps (SCBs) and speed control humps (SCHs) according to their width. In general, the undulation geometry is a very important factor in changing the shock levels to which passing vehicles are exposed, and accordingly, in reducing the vehicle speeds. This study compares SCBs and SCHs with regard to human health risks using the whole-body vibration (WBV) components (VDV, ${\mathrm{S}}_{\mathrm{e}}$, and $R$) to which vehicle drivers are exposed while passing over the undulations. Because SCBs and SCHs are usually preferred for use in urban road networks, experimental vibration measurements are conducted at 20, 30, 40, and $50\mathrm{km}/\mathrm{h}$ vehicle speeds. In order to demonstrate the effects of different vehicle types, vibration measurements are repeated in the same driver and undulation geometries with sedan, hatchback, and station wagon vehicles for each measurement speed. The evaluations use standard evaluation methods which are frequently preferred in the world in WBV analysis. Using these methods, vehicle type and vehicle speed effects are reciprocally evaluated considering SCB and SCH geometries with equal heights. Use of the SCHs appears to be more suitable for human health in traffic speed management.