Research On Bus Network Optimization Method Based On OD Passenger Flow

Optimizing the structure of public transport network is an important way to solve the problem of traffic supply and demand caused by the continuous expansion of urban population scale and the increase of total travel demand.At the same time,China’s rail transit is in the stage of rapid construction and development.With the continuous change of urban land distribution,the demand and distribution of passenger flow also presents a dynamic change state.How to design a reasonable bus network is of great significance to meet the diversity of passenger travel distance,travel mode and travel purpose and to improve the overall service level of public transportation.This paper mainly aims at promoting the coordinated operation of rail transit and regular bus.The specific research contents are summarized as follows.(1)A bus route optimization algorithm based on multi-layer network fusion are studied.Due to the lack of coordination and connection between bus network and rail transit line,the fierce competition between the two modes of transportation and the low efficiency of bus line network are still prominent,this paper focused on the collinear competition problem between the two modes of transportation,and studied the optimization and adjustment design method of the conventional bus lines that are collinear with rail transit.According to the co-linear position between the two modes of transportation,the conventional bus routes are divided into co-linear segment and non-collinear segment.For the co-linear segment,a route optimization model was established,which aims at minimizing the total travel time cost of passengers and takes the change of the length of the co-linear bus routes before and after route adjustment as the constraint condition.Finally,the greedy principle was used to design the model solution algorithm and applied to the simulation construction data set and the actual case of Xiamen.By comparing the total travel time cost of passengers before and after the route adjustment,we found that the route optimization model and the solution algorithm are effective and feasible.At the same time,the transit line and rail transit are intersected at the rail connecting stations after the adjustment,which effectively utilizes the conventional bus to collect and distribute passenger flow for rail transit,promotes the mutual cooperation between the two modes of transportation and achieves the purpose of integration.(2)To solve the problems of low efficiency and poor reliability of public transit system caused by unclear functions of public transit lines and unreasonable allocation of transport capacity,the optimization design model of public transit network was further proposed.Firstly,the paper discussed the main factors,models and methods of bus network optimization design,and analyzed the objective functions and constraints commonly used in bus network optimization.Secondly,the optimization model of bus line network and K shortest path algorithm were established from the perspective of travelers and bus enterprise’s operating interests.The paper established the K shortest path algorithm to generate the candidate bus route set,so as to make the operation efficiency of the bus route as high as possible on the premise of guaranteeing the shortest travel time of passengers.Finally,we designed the genetic algorithm to solve the line network optimization model and the model was applied to Xiamen passenger travel card history data sets.Through average length of bus lines,non-linear coefficient,passenger turnover efficiency and othe indicators,we can conclude that the line network optimization model and the algorithm are feasible and effectiveness.