Numerical investigation of bus stop structures in Seoul for the reduction of fine dust entry

Fences and air curtains can effectively reduce fine dust entry into roadside bus structures, thus decreasing the exposure of passengers to particulate matter. In this study, bus stop structures that reduce the entry of fine dust formed or dispersed by vehicles was derived through simulation models. These bus stop structures consist of a fence that blocks particle entry from a relatively low position in front of the bus stop and an air blast structure that blocks particle entry from a relatively high position. Three bus stop styles were considered: a bus stop without a fence, that with a vertical flat fence, and that with a vertical curved fence toward the road. Among these styles, the curved fence model was superior to other models, and particle entry into the bus stop was estimated to be reduced by 15.5 % for the curved fence model compared with the model without a fence. After the selection of the fence model, three air blast structures were considered: canopy, wall, and fence types, which blast air from the ceiling of the bus stop, toward the direction of the road from the rear wall of the bus stop, and upward from the top of the curved fence, respectively. The canopy-type air blast structure was found to be the most effective in decreasing particle entry into bus stops, with a reduction rate of 88 % compared with the reference model without a fence and air blast system.