Study On Rial Transit Passenger Flow Assignment Based On Time-spatial Network

After entering twenty-first Century,the modernization level of the domestic cities has been improved rapidly,and the people’s travel has become more frequent.In this context,traffic congestion has gradually become a bottleneck restricting the sustainable development of cities.Under the national policy encouragement,a large amount of cities are working hard on the construction of urban rail transit systems in order to reduce the pressure on ground transportation.Meanwhile,aiming to be more convenient and effective,most of the urban rail transit systems are using " seamless-transfer ".Under this condition,the transfer information of passengers will not be recorded,which will also bring much difficulties to the operation and management of the system.The main content of this paper is to focus on the problem of passenger flow assignment of urban rail transit.According to the collation of relevant literature,the related researches in China are mainly focused on static assignment.The static distribution method hardly considers the characteristics of passenger flow in time-dimension,and provides limited help to the operation organization of urban rail transit.In this paper,based on the method of time-spatial network,the dynamic distribution method of rail transit is studied.The main work contents are as follows:(1)The relevant theory of city rail traffic flow distribution are summarized,and based on the city rail transit network time-varying characteristics,the concept of time-space network is put forward.Then this paper introduces the elements of time-spatial network,and summarizes the method of expanding the spatial network into time-spatial network based on the timetable.(2)Based on the analysis of the relevant survey data,the key factors that influence the passengers’ path selection are screened out.Considering the travel time,transfer situation and congestion situation,a path impedance function based on travel time is constructed.At the same time,in order to reflect the time and space characteristics of the path more accurately and comprehensively,combined with the habit of passengers’ path selection,a path impedance function based on travel distance is proposed,and the comprehensive impedance function of the path is constructed by combining the two.(3)Considering the randomness of passenger route choice behavior,a stochastic user equilibrium model based on the time-space network is constructed and the effective path search method of time-space network are summarized.Then this paper put forward to solve the model by using the improved MSA algorithm,and the local rail transportation network in Shenzhen as an example,to verify the feasibility of the model and algorithm.