Research Of Collaborative Scheduling For Overlapping Segment Of Bus Routes

Bus routes are characterized by overlapping segment as the density of bus networks in cities becomes denser.Overlapping bus routes can meet the uneven demand for bus travel between the central and peripheral areas of the cities.However,interventions between vehicles and passenger flows of different bus routes in the overlapping operation segments can diminish bus service reliability and multiply bus scheduling complexity.To reduce passenger travel costs and improve the efficiency of overlapping bus services,the paper considers the interaction between overlapping bus vehicles and passenger flows,and uses bus schedule optimization and vehicle dynamic control strategies to establish static scheduling,dynamic scheduling and emergency scheduling optimization models for bus vehicles operating in operating bus routes segment.And the model and the proposed scheduling method are validated through case studies and simulations.Firstly,the bus static scheduling method is used to collaboratively optimize the schedules of overlapping bus routes.Based on the analysis of the mechanism of multiroutes bus bunching,the ideal headway calculation method for mixed fleets in the overlapping segment is derived.In order to avoid the multi-routes bus bunching at the first stop of the overlapping segment,the first stop schedule of the overlapping segment is proposed based on the criteria that the bus vehicles in the overlapping segment should operate at the ideal headway as much as possible,and the three different requirements of uniform headway,fleet size maintenance and both are proposed respectively.In order to further select a suitable scheduling strategy for overlapping bus routes,a model of cooperative optimization method selection criteria for the first stop schedule in the overlapping segment is established according to the overlapping routes topology.Secondly,the bus dynamic scheduling method is used to control the operation status of bus vehicles operating on the overlapping segment.Considering that the bus bunching may occur during the operation of vehicles in the overlapping segment due to the volatility of passenger demand and other reasons.And this cannot be avoided by a simple static dispatching strategy.The study describes the bus operation process in the overlapping segment and the interaction effects between vehicles of different bus lines.A cooperative vehicle operation scheduling model is constructed based on the stopping control and speed induction strategies to prevent the multi-routes bus bunching in the overlapping segment.In order to promote the cooperative transfer of passengers between overlapping routes and reduce the waiting time of passengers in the overlapping segment,the interaction effects between passenger flows of overlapping bus lines are analyzed based on the speed guide and green light extension strategies.The overlapping bus cooperative transfer scheduling model is constructed to increase the overlapping bus cooperative transfer opportunities and meet the passenger transfer demand.Finally,the emergency bus dispatching method is used to evacuate vehicles running in the overlapping bus routes under sudden large passenger flow situations.When a sudden increase in passenger flow occurs at an overlapping segment stops,passengers gather at the overlapping segment stops.This not only affects the operation of the bus vehicles on the bus route,but also has an impact on other overlapping bus routes.In order to complete the evacuation of passengers as soon as possible and reduce the impact of sudden large passenger flows on the transportation system.An emergency evacuation model for overlapping buses under sudden heavy passenger flow scenarios is established based on bus stop-skipping scheduling strategy to quickly evacuate passengers gathered at bus stops.The case simulation results show that if the vehicles of the overlapping bus routes operate according to the prepared schedules and the vehicle operation status was control by the proposed dynamic scheduling method,the multiline bus bunching phenomenon at the overlap segment stop was eliminated and there are 45 effective collaborative transfer opportunities was provided for the 47 buses entering the overlapping segment to meet the demand of passengers for quick transfer.In addition,the emergency dispatching method resulted in a 29% to 48% reduction in the average waiting time of assembled passengers in sudden large passenger flow situations and a significant reduction in the average waiting time of passengers in the emergency evacuation process.Therefore,the proposed collaborative scheduling method for overlapping bus routes can solve the problems of multiline bus bunching,long passenger transfer times,and low efficiency of emergency bus evacuation due to the interaction of vehicles and passenger flows on overlapping bus routes.The research results can improve the theoretical system of urban bus scheduling system,which is of great significance for improving the quality of bus services,increasing the attractiveness of urban bus and relieving urban traffic congestion.