Study On Traffic Congestion Propagation Modeling And Passenger Flow Control Strategy Of Subway

Urban rail transit has the advantages of large traffic volume and high on-time rate,so the scale of urban rail transit construction in China is gradually expanding.As a result,urban rail transit has become the first choice for more and more residents,and the large passenger flow of urban rail transit has become a normal phenomenon.The impact of continuous large passenger flow will bring huge operating pressure to urban rail transit and reduce the operating efficiency of rail transit;The overcrowding caused by large passenger flow in the station is likely to lead to accidents of passengers,endanger the personal safety of passengers and increase the safety risk of station operation.Therefore,this paper studies the congestion transmission of large passenger flows in urban rail transit and reveals the impact mechanism of congestion transmission in urban rail transit.;the paper also puts forward the relevant passenger flow control strategies and methods from the aspects of train transportation organization optimization and passenger flow inflow control.It provides a theoretical basis for improving the operational efficiency,safety and service quality of the line,and also provides a certain basis for the study of passenger flow control.Firstly,analyzes the classification,characteristics and spatial and temporal distribution characteristics of large passenger flows of urban rail transit.In terms of the characteristics of time distribution,the daily passenger flow distribution,weekly passenger flow distribution,short-term passenger flow distribution and holiday passenger flow distribution were studied,and it was found that the daily passenger flow was of double-peak type,and the change of weekday passenger flow was more obvious than that of weekend passenger flow.In terms of spatial distribution characteristics,the passenger flow distribution in section and upstream and downstream passenger flow distribution in the same station are mainly studied,and it is found that the passenger flow distribution in section is uneven.The passenger flow in the upstream and downstream direction of the same station is of single peak type,and generally only the single direction is in the crowded state of passenger flow.And summarizes the existing passenger flow control strategies from two aspects: transportation organization optimization and passenger flow inflow control.Analyzes the problem of passenger flow congestion from three aspects: the life cycle of passenger flow congestion,the causes of its formation and the influencing factors.In the classical SIR model,the propagation rate and evacuation rate of passenger flow congestion are introduced to study the law of passenger flow congestion propagation and dissipation law of passenger flow congestion.Combined with the known classification of passenger flow state,this paper defined the passenger flow state of Guangzhou metro line 8 as a case study,and analyzed the impact of the crowd-flow state on the crowd-flow transmission range of stations.It was found that the crowd-flow transmission range and time period were different when the large passenger flow congestion occurred at the first and last stations and intermediate stations.Generally,when congestion occurs at the first and last stations,the transmission range of congestion is very small.When the middle station is congested,it will spread along the upstream and downstream direction simultaneously.It provides the basis for the study of large passenger flow control strategy.The problem of insufficient capacity for train,a train station capacity optimization method,constructed by the station and the line of vehicles as decision variables,passenger travel time and train stop time as objective function,with passenger demand,traffic organization and arrival,security tracking interval as constraint conditions,such as multi-objective optimization model,the model is solved by exhaustive method.Taking Guangzhou metro line 8 as an example,passenger travel time and train stop time can be greatly shortened.According to the transportation capacity formula of the line,the transportation capacity in the upward direction increased by 5.26% and that in the downward direction increased by 4.3%.Aiming at the crowded line,a single-target line current limiting model is built from the passenger's perspective.With the minimum delayed passenger volume as the optimization objective,the constraints of passenger flow demand,interval transport capacity and passenger flow control intensity are carried out to obtain the optimal station inflow,number of flow limiting stations and control period under coordinated and uncoordinated flow limiting conditions.LINGO software was used to solve the model,and the uplink direction of Guangzhou metro line 8 was taken as an example for application.When coordinated flow limiting measures were taken,and when coordinated flow limiting measures were not taken,the optimal arrival amount and flow control rate of each station at different time segments were obtained.It is found that the adoption of station coordinated current limiting measures can disperse the congestion pressure of a single station to multiple stations and reduce the security risk brought by the overcrowding of a single station.