Modeling electric bike–car mixed flow via social force model

Abstract

Because of the convenience and the quickness, electric bikes gradually become the main travel mode of urban resident in China, and electric bike–car mixed flow becomes the new characteristics of urban traffic flow. But their role in mixed traffic flow and their effects on cars have become important problems for transportation designers. Mixed traffic flow simulation model provides the designers an effective tool to acquire the relation between flow and density in a new design scheme, achieve solutions for optimal design features before implementation, and help to make the design more rational. Based on the electric bike–car mixed flow characteristics and social force model, this article proposes a microscopic model which can represent the behavior of electric bike–car mixed flow in road segment. First, the inner and outer forces determining the movement mechanism of electric bikes and cars were analyzed, respectively; second, we developed a modified social force model to describe the electric bikes and cars behaviors; third, the social force model was modified and extended for mixed traffic flow by considering the interactions between electric bikes and cars, lane-changing behavior, and conflict avoidance behavior. The interaction parameters of the social force-based model for electric bike–car mixed flow are estimated using empirical data. The established microscopic model can be used to estimate critical flow of separating vehicle and electric bike and determine proper electric bike lane width according to different electric bike requirements by simulating.