Traffic State Estimation And Feature Analysis Method For Urban Expressway Based On Multi-source Data

Urban expressways are rapid traffic corridors in cities,making positive contributions to urban traffic with larger service capacity and higher service level.At the same time,traffic safety problems,congestion problems and congestion-induced vehicle emissions,environmental energy problems of urban expressways are constantly troubling traffic managers,and seriously affect the service level and traffic efficiency of expressways.In order to understand the traffic operation characteristics of expressways,improve the comprehensive service level of expressways,and make full use of the traffic data with different accuracy,breadth and detection contents deployed on expressways,this paper conducts a research on traffic state estimation and feature analysis of urban expressways,which bases on multi-source data and a large amount of detection data of urban expressways.The purpose of this paper is to provide help to alleviate the traffic problems of urban expressways by analyzing the traffic state of urban expressways.Firstly,the data properties and preprocessing methods of Global Positioning System(GPS)、Automatic Vehicle Identification(AVI)and Geographic Information System(GIS)data are investigated.It provide data support for the traffic estimation and analysis.Secondly,a dispersion of vehicle speed based on average speed and standard deviation of speed is proposed.The VISSIM simulation is used to explore the potential relationship between dispersion and traffic parameters for traffic states,which provides a preliminaries for incorporating dispersion into traffic state.Then,several traditional traffic state estimation methods including Fundamental Diagram Of Traffic Flow and Level of Service are compared.The limitations of these methods in estimating traffic flow state are analyzed,and the traffic state estimation method of urban expressway based on normalized spectral clustering algorithm is introduced in terms of algorithm principle,implementation process and evaluation index.Finally,the traffic state estimation and analysis are carried out on the basic section of Shenzhen expressway.The GPS data,AVI data and GIS data are used to obtain the basic traffic parameters of the studied road section,the proposed speed dispersion and estimation method are combined to complete the state estimation.Parameter characteristics of the estimation results are analyze to prove the effectiveness of the research method.