Research On Bus Shuttle Scheme Under Urban Rail Transit Operation Disruption

The large-scale development of urban rail transit(URT)intensifies the operation risk of system.Once the subway line service disruption occurs,the transportation capacity of system will decline and the travel routes of passenger flow will be affected.If the disruption occurs in peak hours,it will certainly lead massive passenger flow stranded in the rail transit network and bring greater operational risks.Under emergency conditions,when the adjustment strategy cannot meet the demand of passenger flow,public bus resources should be considered to replace the transport function of URT.To reasonably plan bus resources,relieve the evacuation pressure of passenger flow in urban rail transit network,and minimize the travel delay and accident loss,this paper proposes a bus shuttle optimization scheme considering road traffic characteristics,to meet the evacuation demand of stranded passenger flow under service disruption of urban rail transit.The main contents are listed as follows:1.Construction of operation disruption scenarios of urban rail transitBased on the traffic adjustment strategies of urban rail transit system under operation disruption,including train density adjustment,routes adjustment,stopping scheme adjustment,etc.Combined with the structure of interrupted traffic network,the affected urban rail transit lines are divided into different categories of sections,to determine the affected line set,the affected station set and the affected passenger flow set in urban rail transit network.In this way,the construction of the operation disruption scenario of urban rail transit lines is completed2.Passenger flow demand analysis under disruption scenarioThe travel time chain is constructed based on the passenger travel path under service disruption of urban rail transit lines.This paper proposes that passengers’ travel choice is mainly based on perceived travel cost and gives a calculation method.Based on the disruption scenario and taking the affected passenger flow as research object,the effective alternative routes for the interrupted lines is generated.Based on the cumulative prospect theory,the cumulative prospect value of each effective alternative path is calculated,and the path selection model for affected passenger flow is constructed to determine the bridging demand of affected passenger flow in the urban rail transit network.3.Generation of bus bridging emergency shuttle schemeConsidering the influence of road traffic status on vehicle speed,the urban road traffic status grade table with traffic flow density as the index is defined,and the calculation method of emergency bus average speed under different road traffic status is proposed.The bridging stations and path arcs are defined based on the line set and station set under operation disruption scenario of subway lines.The emergency bus bridging network is built according to the location of the service-disrupted station and the return line configuration of the stations at interrupted lines.This paper firstly analyzes the advantages and disadvantages of different bus stopping mode and proposes the stopping idea of feeder-bus by skipping station.Based on the bridging demands of affected passenger flows in the urban rail transit network,an optimization model of emergency bus shuttle scheme is established with the objective of minimizing the comprehensive cost of passenger travel and emergency bus operation,and the constraints of passenger flow conservation,emergency bus departure frequency and occupancy rate are considered.Considering the maximum passenger flow of disruption section and the bus utilization rate,a calculation method of the number of feeder-bus is given.4.Case validationTaking the emergency bus bridging practice of Guangzhou metro on May 3rd,2018,as a case,based on the disruption scenario of urban rail transit subway line,the number of affected lines of Guangzhou metro network is four in total.The case analyzes the bridging passenger flow demand for a total of 106 subway stations and a bus bridging emergency shuttle scheme is generated.Compared with the single-mode bridging scheme,the feeder-bus number of multi-mode bridging scheme is saved by 8.33%,and the total cost of bridging system is reduced by 25.56%.The results verify the effectiveness of the model in this paper.Figures 36;Tables 18;Reference articles 88...