Mitigating Risks at Bus Stops: A Study of the Effectiveness of Bollard Systems

This work assesses the effectiveness of a proposed interconnected multi-bollard design in protecting bus stop occupants from incoming vehicles. A detailed model of a 3-bollard system was developed in ANSYS LS-Dyna®, which included the bollards, their underground support structures, and the rebars connecting the bollards. The bollard system was composed of 116 parts with a total of 443,799 elements. The system model was merged with a detailed model of a 2007 Chevrolet Silverado, 4-door crew cab pickup truck with 603 parts with 251,400 elements developed by the Center for Collision Safety and Analysis [1]. The vehicle was simulated to impact the bollard system at speeds between 15 and 90 mph at angles ranging from 0° (normal to the bollard system) and 90° (parallel to the bollard system). Impacts were also made at various degrees of centeredness, with cases showing response from impact at the center of bumper, as well as at the edge of the bumper. With each case, vehicle velocity and acceleration were monitored using virtual accelerometers, placed in the vehicle to assess the effectiveness of the bollard to stop the vehicle. Simulation results show that the bollard was able to stop a vehicle traveling normal to the bollard system, impacting the center of the bumper at speeds up to 45 mph. However, the vehicle would continue past the bollard system at higher speeds.