Methodology Of Bus Network Optimization And Adjustment Under The Operation Of Urban New Rail Transit Line

In order to solve the traffic congestion problem, rail transit networks have been planned and constructed in many big cities in China. To construct a reasonable integrated network of rail transit and bus is the key to give full play of transit resource allocation, and to improve transit service quality. Due to the sequential character of rail transit lines construction, in practice, the programme of bus network optimization and adjustment is usually planned in coordination with the new rail transit line. The methodology of bus network optimization and adjustment with new rail transit line in operation is worked on. The following six parts are mainly contained:(1) The characteristics of bus network are discussed based on new rail transit line. On the basis of comparing the characteristics of rail transit and bus, classification and characteristics of bus lines are analyzed considering the competition and cooperation relation, topological structure relation and function integration relation with rail transit line respectively. In addition, the characteristics of the integrated network of rail transit and feeder bus, of the rail transit and bus are proposed respectively.(2) The characteristics of bus network optimization and adjustment with new rail transit line under operation are investigated. From the perspective of urban development, travelers’demands, and the supply of the transit system, factors influencing bus network optimization and adjustment are analyzed. The overall principles as well as the optimal strategies of bus network and line optimization and adjustment are proposed.(3) A heuristic algorithm for generating bus candidate lines is investigated. When a rail station that requires feeder service is given, a heuristic algorithm for generating feeder bus candidate lines of the rail station is proposed. For the integrated network of rail transit and bus, a heuristic algorithm for candidate lines generation of existing bus lines is presented based on topological relationship with the new rail transit line, and a heuristic algorithm for candidate lines generation of new bus lines is also proposed based on integrated function relationship with the new rail transit line.(4) With the feeder bus network which offers passenger feeder service for rail transit station as the object of study and the feeder demand as input parameter, a methodology of feeder bus network design is proposed. The close relationship between feeder bus supply and the demand for feeder bus network service, the schedule coordination between feeder bus timetable and arrival time of rail transit station are both taken into consideration. A multi-objective programming model for feeder bus network design is proposed to simultaneous optimizes feeder bus route alignment and timetable. Based on genetic algorithm and variable neighborhood search, a genetic-variable neighborhood search algorithm is developed to get Pareto solution set of the model. A numerical example is used to verify the proposed mathematical model and the solution algorithm.(5) With the integrated network of rail transit and bus network as the object of study and optimizing performance of the integrated network as the goal of study, a methodology is proposed for bus network optimization and adjustment based on new rail transit line. With the objectives of maximizing satisfied transit demand, maximizing rail transit demand, minimizing the average transit user cost, minimizing operation cost and minimizing used fleet size, a multi-objective programming model is formulated for bus network optimization and adjustment. The alignment and operational parameters of bus lines are both optimized by the proposed model. Based on the algorithm for transit efficient path search and computational procedure for integrated network system performance, a genetic-variable neighborhood search algorithm is developed to get Pareto solution set of the proposed model. A numerical example is used to verify the proposed mathematical model and the solution algorithm.(6) Rail transit line No.1in Zhengzhou taken as the background, a real example is used to verify the practical value and significance of the study.