Study And Simulation On The Ca Model Based On The Characteristics Of Mixed Traffic Flow At Intersections

Mixed Vehicle-bicycle traffic is the typical characteristics of urban traffic in China. The intersections are important nodes of road network, they collect large quantity of mixed vehicle-bicycle traffic flow from different directions, thus generate a lot of vehicle-bicycle interference, which lowers the capacity of intersection and increases the potential traffic accidents as well. Because the existing microscopic traffic models are inadaptable to the mixed traffic environment at our country’s intersections, it’s of great importance to establish a microscopic model that could reflect the characteristics of mixed traffic flow.Firstly, the data that reflects the microscopic characteristics of the motor vehicle and bicycle in road section and intersection is collected through video. Then, the traffic parameters of bicycle and vehicle can be obtained by analyzing the bicycle and vehicle traffic characteristics in four aspects, i.e. acceleration, speed, density and space headway. Meanwhile,the commonly seen vehicle-bicycle interference phenomenon at intersection-the mutually crossing behavior between right-turning motor vehicle and straight-going bicycle-is selected to find out the characteristics of vehicle-bicycle interference. Besides, the choice model of the lag of bicycle crossing motor vehicle and the gap of motor vehicle crossing bicycle are established according to the analysis of the microscopic crossing behavior between motor vehicle and bicycle as well as the survey data.Secondly, NS-BCA model is established on the basis of coupling the NaSch model with BCA model and drawing up rules of the lag of bicycle crossing motor vehicle, the gap of motor vehicle crossing bicycle and the disposal when conflict areas are occupied, which are in line with the characteristics of mixed traffic flow.Finally, the NS-BCA model is simulated. And the simulation results indicate that the relationship between vehicle-bicycle conflict and the vehicle arrival rate verify the reasonableness of the model. Furthermore, the mixed traffic interference mechanism is investigated based on the analysis of the relationship between flow and vehicle arriving rate and traffic flow phases.