Approach To Passenger Flow Regulation Of Urban Mass Transit Network

Urban mass transit (UMT) attracts more and more passengers because of fast, punctuality, safety and environmental protection. Capacity supplied can not meet passengers’demand. Thus the distribution of passenger flow is unreasonable, such as serious congestion, overload delay and destination unreachable. These bring strong negative impact on the quality of travelling and bring down the service quality of network. Aiming at the contradiction of supply and demand, the approach to passenger flow regulation of UMT is proposed to adjust supply and demand to optimize the matching of them, and to improve the quality of travel and service of network.The theory and methods about passenger flow regulation are researched in this paper, which contains several aspects as follows:(1) The model of urban mass transit operating network (UMTON) is built.Analyzing the physical structures, schedule and features of travelling in urban mass transit network. The UMTON consists of supply subnet, demand subnet and passenger flow subnet. The essential elements and hierarchies in UMTON are described. The formal descriptions about UMTON are presented. The features of constraints on supply in UMTON are analyzed. The appearance and movement of passenger flow, the change of available capacity and passengers’choice are explained.(2) The framework and methods of passenger flow regulation are put forwardThe common phenomenon reflecting contradiction of supply and demand are concluded as congestion, delay and interruption of passenger flow. The typical contradictions are extracted as passenger flow exceeding limit of capacity, overlong delay and destination unreachable. The reasons of contradiction are analyzed. Capacities supplied and needed are discordance in space and time. Passengers can not master the correct information about trips which are decided by the remained capacities of UMT. The framework and methods of flow regulation in UMT are put forward. The methods are realized by adjusting supply and demand. The method of adjusting supply consists of optimizing schedule and changing physical network. Micro-adjusting in station operating to limit the passenger flow is called passenger flow control. The method of adjusting demand mainly focuses on passenger guidance by information. Aiming at the bottleneck of passenger flow regulation, the passenger inflow control with constraints on volume and the passenger guidance based on accessibility are researched deeply. The necessity and tactics of both methods are analyzed.(3) The model of cooperative passenger inflow control of network with constrains on volume is built and solved.The objective of model is to minimize the average delay time and the maximal delay time with constraints on capacity of waiting nodes and trains," schedule and travel demands. The Particle Swarm Optimization considering the reason of exceeding capacity is used to solve the model. Both of the static route choice and equilibrium assignment are used when loading demand. The travel demands are loaded by the way of simulation. The experiments about controlling total inflow and controlling inflow in different direction are carried out. The key indicators of model are compared with control and without control. The positive effects of equilibrium and controlling inflow are proved. The effectivenesses of model and solving algorithm are verified.(4) The model of passenger guidance based on accessibility is built and solved.The framework of model and the set of guidance information based on accessibility are proposed with driving of demand and constraints on supply network. The algorithm of solving latest departure time, optimal accessible path and K optimal accessible path are presented. The experiments on real UMT network and schedule are carried out. The results of experiments demonstrate the change of accessibility and the dynamic of information about passenger guidance. In addition, the effectiveness of regulating the demand of passengers by the way of passenger guidance based on accessibility is discussed.The innovative contributions in this paper are as follows:(1) Operating network with multi hierarchies and multi characters is built, which can reflect the supply capability, travel demand and the result of mapping supply and demand.(2) The typical contradictions are concluded as passenger flow exceeding capacity bought by flexible constraint of volume, overlong delay brought by overlapping demand, and destination unreachable brought by time constraints. Aiming at solving these contradictions, the frameworks of passenger flow regulation are proposed.(3) The necessity of passenger inflow control in scale of network is illustrated when the safe capacities of volume should be satisfied in the waiting nodes in transfer stations. The model of cooperative inflow control with constraints on volume are built and solved.(4) In terms of transfer disconnection, the existence of destination unreachable is illustrated. The necessity and effectiveness of passenger guidance based on accessibility are analyzed.Based on the relationship and contradiction of supply and demand in UMT, the theory of passenger flow regulation is proposed. The framework of passenger flow regulation is built. The methods are discussed. The model and solving algorithm of cooperative passenger inflow control and passenger guidance considering the constraints of operating network are presented. These work provides the approach to optimize supply and demand, deduces the contradiction of supply and demand, supports the safety, efficiency and service quality of UMT network, and laies the foundation of theory and engineering practice of passengers flow regulation.