Research On The Identification Method Of Region Road Network Traffic Conditions Based On Macroscopic Fundamental Diagram

With the continuous development of the economic society,the possessing capacity of automobile keeps on the increase which causes traffic congestion more and more serious.As well as the negative impact on the environment and economic society now,At present traffic congestion management is not just confined some certain intersection or section,but need to combined with reasonable analysis of the regional road network.Therefore analyzing traffic flow theory fundamentals and the characteristics of the regional road network traffic operation,Comprehensively identifying the traffic status of regional road network by scientific methods,It will be of great significance in overall evaluation of the traffic status.Firstly the thesis presents the basic relationships among the three parameters of the macroscopic fundamental diagram,which theoretically demonstrates its prevailing objective facts.Secondly in the progress of identifying the recurrent congestion of the regional road network,Spatial clustering with noise based on the density is used.the algorithm includes description of vehicle trajectory: such as latitude and longitude coordinates,timestamp,instantaneous velocity etc.In the process of dividing the regional network status,shoule depend on the size of the study area,taking the appropriate width of the grid size and defining a congestion frequency C for each grid,Measuring the congestion of a grid by the size of the C value and the speed change within the grid.Then during the regional road traffic division,the thesis referring to the classification in?Urban Road Traffic Management Evaluation Index System?,divides the regional road network traffic status into five grades according to different types of cities.Finally,according to the rental vehicles GPS data in Tian distract of GuangZhou city of Guangdong province.Using the method of this thesis to identify the status of the regional and classify them,according to the research results,the method is of great importance in the identification of regional traffic conditions.