Dynamic Comprehensive Traffic Index Based On Network Of Multiple Travel Modes

With the rapid development of China’s economy and the continuous advancement of urbanization,urban traffic congestion has become increasingly prominent.Currently congestion indicators are mainly based on car operation data to reflect road traffic conditions,however,with the development of various modes of transportation,especially public transport travel,which has been advocated vigorously,there is a lack of a dynamic evaluation method to evaluate the operation of urban comprehensive transport.In this context,this paper intends to establish a multi-mode travel network and design a traffic index reflecting the comprehensive traffic operation.Firstly,through the literature review of traffic operation evaluation model,multiply travel modes model,optimal path planning model and comprehensive traffic index model,this paper puts forward the shortcomings and deficiencies of current research,and establishes the research direction of this paper.Secondly,it analyses the travel characteristics of four kinds of travel modes which are widely used at present:car,bus,subway and slow traffic,and introduces the urban traffic operation data acquisition system and the format and information of the traffic data collected by the system.Through data cleaning and pre-processing of raw data,the influence caused by errors of data acquisition system and random errors is reduced.Based on the effective data of traffic operation,the operation characteristics of different traffic modes are analyzed,and a network of multiply travel modes model is established based on the travel characteristics of different travel modes.Multiply traffic modes network includes four sub-networks:car network,bus network,metro network and slow traffic network.It connects network nodes through transfer arc and simulates the behavior of up and down traffic network through the arc of up and down network.It is a multi-level three-dimensional traffic network.Thirdly,based on the dynamic speed data acquired by the traffic data acquisition system,combined with the length of the road section,the traveling time of the arc section in the multi-mode travel network is calculated.The transfer time is obtained based on passenger arrival model,and the time of getting on and off the Internet is obtained according to the actual situation.The breakdown of the transfer process is also converted into travel time.Then the OD pairs in the network are determined,and the total travel time model is established based on the above travel time.When the travel path is feasible,the optimal path is solved by Dijkstra algorithm as the travel path of the OD pair in that period.The total travel time is converted into a traffic index,which is used to evaluate the comprehensive traffic condition.Finally,this paper designs an application case and carries out application analysis.It abstracts the road network around Beijing Jiaotong University and CBD in Chaoyang District into a multiply travel modes as two cases.The OD pairs are selected and the traffic index is calculated by the dynamic comprehensive traffic index calculation method proposed in this paper.The results are compared with those obtained by the traffic index calculation method based on travel time ratio,which proves the feasibility and validity of the method.