Study On Operational Schemes Of The Express And Local Trains For Urban Transit Based On Muti-species Flow

With the continuous expansion of the city,urban residents not only require comfortable and fast travel,but also require high line accessibility,so the development of urban rail transit is faced with great challenges.For the development of urban rail transit in China,the combination operation mode of express and local trains provide a brand-new operation mode,which can better meet the needs of long-distance passengers,increase the utilization rate of trains,effectively reduce the cost of operating enterprises and improve passenger satisfaction,and is a new and inevitable development trend.In this paper,the basic concept of express and local trains is put forward.From the perspective of operators and passengers,the advantages and disadvantages of express and local trains are summarized compared with the station parking scheme,and the passenger flow characteristics and line characteristics of running express and local trains are pointed out.An integer programming model with the minimum total cost of operators and passengers is constructed,and a solution algorithm is proposed.The passenger flow allocation based on multicommodity flow is proposed,the travel cost of passenger route is determined,and the passenger flow allocation model based on multicommodity flow is established.The details are as follows:First of all,it summarizes the development experience of foreign express and local trains operation modes,and on this basis,it combs and summarizes the development process of express and local trains in China.This paper expounds the basic concepts and organization types of f express and local trains,discusses the imbalance of passenger flow from two aspects of time and space with the support of line passenger flow data and corresponding line data,and holds that running express and local trains can solve the imbalance of passenger flow in time and space.And discusses four factors that have influence on the combination operation of fast and slow cars.Secondly,carry out passenger flow distribution.Under a certain scheme of express and local trains,the service network of express and local trains is constructed,and the passenger ride process is described.Based on the passenger travel strategy,the travel route time cost of passengers is constituted and solved,including waiting time for trains,waiting time for trains at the running side and waiting time at the transfer side.A passenger flow allocation model based on multicommodity flows is established,and the corresponding algorithm is proposed.Thirdly,establish an optimization model.The optimization model of express and local trains operation scheme is constructed with the cost of operating enterprises and passenger travel cost as the objective function.Taking the stop sequence of express-local train and the number of departures of express-local train as the decision variables,considering the factors such as line capacity,train capacity,train full load rate and stop scheme.The genetic algorithm is chosen and the corresponding design is carried out.And last the optimal solution of the model is obtained.Finally,an example is analyzed.According to OD passenger flow and line conditions of Line A,the rationality of adopting the combination operation mode of express and local trains on Line A is analyzed.Using genetic algorithm,the optimal stop plan of express train on Line A and the departure times of two trains are solved and then compared with the stop plan of station under the same conditions.The model shows that running express and local trains on Line A is helpful to save the cost of operating enterprises and shorten the travel time of passengers.