车路协同环境下重叠线路公交车速诱导策略

To prevent bus bunching and traffic bottlenecks near stops in overlapping route segments, a dynamic dispatching model was proposed. The model used a speed guidance strategy to adjust the operation status of the bus. Considering the passenger demand and bus headway when each line was operating independently, the bus operation dispatching method was adopted under a cooperative vehicle infrastructure (CVI) environment. To achieve the optimization objectives, the buses on each line can be maintained in the headway of the lines and avoid bus bunching at the stops in the overlapping route segments as much as possible. The proposed speed guidance dispatching strategy in the CVI environment guides the buses of each line to enter the overlapping segments smoothly and realize real-time control of the bus according to the real-time passenger demand and road traffic conditions. A heuristic algorithm was developed to calculate the bus entry time for overlapping route segments, and a genetic algorithm (GA) was used to determine the optimal speed of the buses between stops in the overlapping route segments. The dynamic scheduling process of the bus in overlapping route segments was realized. Three overlapping bus lines in the operation section of Harbin City were considered for a real case simulation analysis. The operation status for a total of 47 buses on the three lines between 12 stops in the overlapping route segment was optimized and dispatched. The results show that after using the proposed heuristic algorithm, buses could enter the overlapping segment evenly. By comparing the running state of buses before and after the optimization of dynamic scheduling, the phenomenon of bus bunching was found to have decreased from a maximum of six in a single stop to zero, which achieved the goal of avoiding bus bunching to the greatest extent. In addition, the speed guidance strategy not only avoids bus bunching on different lines in the overlapping route segments but also adjusts the headway deviation between adjacent buses on each line. The maximum headway deviation of line 1 was reduced from 55% to 30%. The maximum headway deviation of line 2 dropped from 25% to 13%. The maximum headway deviation of line 3 dropped from 23% to 18%.