Optimization Of Feeder Bus Lines For Urban Rail Transit Stations

Prioritizing public transportation is an important way to solve the problem of urban traffic congestion.As the backbone of the urban public transport system,urban rail transit system undertakes the task of long-distance passenger transport on the main transportation corridor.However,the service coverage rate of rail transit lines is very limited,so it is necessary to design an efficient feeder system for them to distribute passenger flow.The last-kilometer problem is an important factor restricting the capacity of rail transit.Therefore,it is realistic and urgent to study the optimization of urban rail transit feeder system.Based on this background,this paper takes the most common fixedroute feeder bus line in the domestic urban rail transit feeder system as the research object,analyzes the influencing factors and mechanism of its operation efficiency by proposing the accessibility index of single line and building the route optimization model of feeder bus network,and discusses some optimization problems related to it.At present,there are a mature rail transit network and a perfect feeder system in some major cities in China and abroad.This paper first makes a comparative analysis of the rail transit feeder systems in Hong Kong,Singapore,Beijing,and Shanghai,studies their characteristics,and analyzes the characteristics and applicability of different types of feeder systems.This paper crawls the routes,stops data,and operation information of feeder bus lines of Beijing and Shanghai,makes a detailed statistical analysis,and summarizes the lines planning and operation characteristics to provide a practical basis for the following optimization research.Secondly,at the level of a single line,this paper proposes an improved accessibility index of feeder lines based on previous studies with consideration of passenger flow competition and passengers’ waiting time among access modes,and takes it as the evaluation index of performance of feeder lines.The effects of line length,station spacing,fleet size,and location of transfer stop on the accessibility of feeder lines are analyzed.The accessibility differences of feeder lines with five forms of routing under different line lengths are calculated and compared by deriving accessibility formulas and building the optimization model of feeder bus routes to solve examples.The conclusion shows that this difference exists,and the feeder lines with different forms of routing are suitable for areas with different passenger flow intensities and rail transit station densities.Finally,at the network level,based on the actual investigation of Beijing microcirculation bus operation,the minimum total cost of feeder bus system is set as the optimization goal,and the optimization model of urban rail transit feeder bus network was built based on the method of column generation.This model includes three kinds of point elements: bus depot,subway station,and bus stop.The Gurobi solver and artificial bee colony algorithm written by Python are used to solve the main problem and subproblem of column generation respectively.The results show that the column generation algorithm is effective in solving this kind of problem.The sensitivity analysis of the parameters shows that vehicle speed,vehicle type selection,and line length are the important factors affecting the operational efficiency of the feeder bus system.With the help of the optimization model,this paper further discusses the critical passenger flow conditions of fixed-route feeder buses.