Study on Characteristics of Multi-Speed Mixed Traffic Flow at a Single-Loop Roundabout

Based on the NaSch model, a cellular automata model of multi-speed mixed traffic flow at single-loop roundabout with injection-roundabout-lane,extraction-roundabout-lane and inner-roundabout -lane is proposed to describe hybrid traffic flow of a single-loop roundabout in real life. In this model, the priority of vehicles in the inner-roundabout-lane and those which firstly reach the merging points are definitely adopted, and the steering probability is introduced to effectively prevent the occurrence of deadlock and avoid the collision between vehicles. Under the open boundary conditions, two kinds of vehicles with maximum speed are injected into the injection-roundabout-lane on the basis of a certain proportion, and the influence of the injection probability and extraction probability on the system flow, average speed and system density under different vehicle mixing proportion coefficients is studied. Simulation results indicate that different vehicle mixing proportion coefficients have different effects on the traffic flow of the system. Besides, the injection probability and extraction probability can only affect the traffic flow of the single-loop roundabout in a certain range. In short, these research conclusions will provide a certain valuable reference for the actual road traffic flow control and management of hybrid vehicles at a single-loop roundabout.