Regional Railway Timetable Optimization Based On Dynamic Passenger Demand

With the acceleration of the urbanization in China,the city size has been increasing and the urban population has increased dramatically.When the capacity of the urban central area becomes saturated,the population will inevitably spread to the suburban area,and the intercourse between the central area and suburban area will be more frequent.In the face of the rapid growth of long-distance passenger demand,subway and bus have been unable to meet this part of passenger demand.The regional railway has the advantages of high speed,large capacity,safe and reliable,so it will become the main transport mode for the residents between central area and suburban area.At presnt,China’s regional railway is still in its infancy,so there are many problems related to plan,design,operation and management being worthy of further study.Timetabling problem is the core content in regional railway organization,and its quality will affects the passenger satisfaction and operation cost.As the train stop plan of regional railway is complex and the passengers want to get on the train as soon as they arrive at station,so the existing methods can not be applied to regional railway.Aiming at this problem,this paper has studied the train timetabling problem of regional railway under dynamic passenger demand.The main contributions include the following aspects:(1)This paper summarizes the present development status of regional railway in major cities at home and abroad,as well as the state of the art of train stop plan and timetable,and gives a comprehensive review of existing problem and shortcoming.(2)This paper analyzes the technical characteristics and passenger flow characteristics of regional railway,and puts forward that the organization of regional railway should adopt skip stop schedule and consider the dynamic passenger demand.The characteristic of determining the train schedule under dynamic passenger demand is studied,and the necessity of the integrated optimization of train stop plan and timetable is analyzed.(3)Aiming at mimizing the passenger total travel time and considering the constrainsts of dynamic passenger demand and train capacity,three optimization models are formulated.The first model fixes the train departure sequence and do not allow the trains to overtake each other at the station.The second model fixes the train departure sequence too,but the adjacent two trains can overtake each other.The third model does not fix the train departure sequence and allow the arbitrary two trains to overtake each other.The three models are solved by CPLEX,and the sensitivity of the parameters in the model is studied.(4)On the basis of section(3),an integrated optimization model of train stop plan and timetable is constructed.Considering the constraints of dynamic passenger demand,train capacity,station service frequency and the number of train stops,a non-linear mixed integer programming model is established to minimize the passenger total travel time.The nonlinear model is transformed into a mixed integer quadratic programming model by using the linearization method,and the integrated model is solved by CPLEX.(5)The models proposed in this paper are used to optimize the train stop plan and timetable of Jinshan line.The results show that the optimization timetabling model based on the dynamic passenger demand can effectly reduce the passenger total travel time and average waiting time,which verify the effectiveness of the proposed timetabling model based on dynamic passenger demand.The integrated optimization mdoel is used to optimize the train stop plan and timetable of Jinshan line.The number of train stops is reduced 8 compared with the practical train stop plan.Compared with the practical timetable,the passenger total travel time is reduced by 6.9%,and the train total travel time is reduced by 6.2%,which proves that the integreated optimization model can simultaneously optimize train stop plan and timetable.