Evaluation And Analysis Of Urban Road Operation Condition Based On DIDI Trajectory Data

With the increasing development of urbanization,traffic congestion has become one of the major social problems in most of the metropolises.Traffic congestion will restrict the development of cities,increase unnecessary social travel costs,and cause a great deal of loss in urban economy.Therefore,the real time and accurate judgment of road running state and long-term continuous monitoring of the changing regularity of road running state has significantly benefits to formulate more reasonable traffic road management policies.In this paper,the trajectory data of floating car from DIDI enterprise and the map matching technology were applied to establish the evaluation system of urban road operation situation from the point-line-area three levels using C#programming language to help process the corresponding data and ultimately construct an urban traffic operation State real-time monitoring system.Firstly,this paper introduced the structure and scope of the vehicle trajectory of the DIDI enterprise and preprocessed the original data including the transformation of trajectory coordinates,the elimination of the bad point data and interpolation processing.Secondly,this paper introduced the common algorithms of map matching and the method of vertical projection and historical trajectory checking,combining the simple and efficient and historical trajectory checking method of the Perpendicular projection method,the synthetic map matching algorithm has high matching efficiency and low matching error.Thirdly,according to the vehicle trajectory data,the traffic flow characteristics of a road are analyzed concretely,the change of traffic flow,velocity and density,and the relationship between the three characteristics,and the change of the characteristics of the working day and non-working day are compared,and the influence of morning and evening peaks on traffic flow characteristics.Then,from the point-line-area three levels,divides different road grades,with the delay index as the evaluation indicator,uses the road traffic flow,assigns different weights to the different rank road to appraise the road network Operation state.The point level is a single section of the Operation State evaluation;The line level refers to evaluating the road running state of different grades;The area level is the evaluation of the overall operation status of the network in a certain area.Finally,according to map matching method and road Operation State evaluation method,on the.Net platform,through the C#programming language,combined with the ArcEngine component library,a real-time monitoring system for traffic condition evaluation is constructed,and all roads in the network are monitored in real time,and the traffic operation status of a certain section,a certain grade road or a certain area network can be evaluated.