Study On Train Routing Scheme Based On Tidal Characteristics Of Passenger Flow In Urban Rail Transit

In recent years,with the advancement of urban integration in China,the city scale has been expanding unceasingly and urban rail transit lines also continue to extend,which helps form a guiding-type line connecting city center and surrounding suburbs as well as produces a special passenger flow tidal phenomenon:in the morning rush hour,the passenger volume in the direction into the city is large and concentrated in a certain section,while the passenger flow in the direction out of the city is relatively small and stable.The passenger space distribution is tidal and unbalanced.If a single routing scheme is still used,it obviously can not adapt to the space characteristics of tidal passenger flow.However,the full-length and short-turn routing scheme can solve the uneven problem of passenger flow tidal phenomenon,so as to better meet the passenger travel demand and to achieve the purpose of tapping the capacity potential through the reasonable deployment of the existing transport capacity.Therefore,according to the spatial distribution characteristics of tidal passenger flow,how to scientifically and rationally select and formulate the train routing scheme has become a worthwhile research and discussion.The main contents of this paper are as follows:(1)The urban rail transit tidal passenger flow are divided into two types of normal and occasional according to its causes,and the spatial distribution of tidal passenger flow is analyzed according to different types of line.The tidal distribution characteristics of tidal passenger flow will be quantitatively described by tidal distribution coefficient.Aiming at the uneven distribution of time and space in tidal passenger flow,the corresponding traffic organization scheme is put forward,and the feasibility and effectiveness of the full-length and short-turn routing scheme to adapt to the spatial imbalance of tidal passenger flow are expounded.(2)This paper analyzes the advantages and disadvantages of different routing modes,the applicable passenger flow conditions and the main factors influencing the train routing scheme,and puts forward the quantitative evaluation index of the application effect of the scheme from the aspects of passengers,enterprises and operational efficiency.The theoretical basis is provided to the establishment of the route optimization model and the applicability analysis of the routing scheme.(3)Taking into account both the guidance of guiding-type line and the operating costs of enterprises,the paper establishes an optimization model of the train full-length and short-turn routing scheme,which takes the reserved trains as the limit of transport capacity and takes minimizing passengers' total waiting time as objective.The purpose of the optimizing model is to improve the level of service,to reduce the number of overload intervals and to achieve the purpose of tapping the potential efficiency through the rational allocation of existing transport capacity.The genetic algorithm is designed and a system for producing and evaluating the train routing scheme is developed,and take a diameter line in A city as an example to verify the feasibility of the model and the feasibility of the algorithm.(4)Compared with a single routing,the result shows that:in the use of the same number of trains,the full-length and short-turn routing scheme can make the total passenger waiting time reduced by 2086.61 minutes,2.37%optimization,and there are a lot of improvement on the maximum section load factor and the load factor's proportionality as well.That is,under the condition of existing transport capacity,the full-length and short-turn routing scheme is beneficial to passengers,operating enterprises and system benefits in face of certain tidal traffic characteristics.Through the sensitivity analysis of the key elements of the routing scheme,the critical tidal passenger characteristics of the diameter line are obtained.When the passenger flow in the turn-back section is about 59%,the tidal distribution coefficient of the line is about 2.5,and the position deviation of the peak is 15%of the total length of the line,the full-length and short-turn routing scheme is advantageous for the passenger.