Study Of OD Rebuild For Highway Netwoek

OD data is an important basic data for transportation planning,management and construction.In the process of urbanization,highway network planning,construction and management put forward higher requirements for frequency and accuracy of OD data updating.Traditional OD acquisition methods need to carry out large-scale manual survey,which has the problems of high resource consumption,low accuracy and long investigation cycle.With the development of information data acquisition technology,the method of estimating regional OD based on traffic volume detection has been developed.Most of the methods take simple road network in small areas as research objects,while the research period is short.This paper is to solve the contradiction between OD demand of highway network planning,construction and management and traditional survey methods and general OD estimation methods.A method of OD rebuild of highway network is proposed to meet the demand of long-term and highprecision OD updating.OD rebuild refers to a method that using history OD database and real-time traffic volume obtained from traffic detection points on the basis of in-depth analysis and accurate grasp of the regional road network structure and development trend.The main contents of this paper are as follows:Firstly,the paper analyses the characteristics of highway network transportation,summarizes the characteristics of highway network OD rebuild method,and on this basis,analyses the principle of OD rebuild method,and puts forward two key problems to be solved in OD rebuild: preparation of OD rebuild basic data,construction of OD rebuild model and algorithm design.Aiming at the first key problem,a priori OD matrix is constructed based on historical OD matrix and traffic prediction technology,and traffic assignment is carried out by using user equilibrium principle.This study mainly analyzed the traffic operation characteristics of research area,and put forward the hierarchical layout principles of screen lines,as entry-exit,interval and regional respectively.According to the principle of integer programming,traffic detection points are laid out in the road section.The traffic flow data of missed traffic detection points are processed by the time series based repair method.Aiming at the second key problem,based on the maximum entropy principle,this paper quantitatively analyses the relationship between the traffic volume in and out of the verification area,OD matrix distribution and road traffic volume,and simplifies the model by using Lagrange multiplier method.Constrained by the conservation of inbound and outbound traffic volume in the verification area,a non-linear programming problem with constraints is established to minimize the difference between the observed values of the sections laid out at the traffic detection points and the rebuild traffic volume.A genetic algorithm is designed to solve the problem.The OD rebuild method is applied to the highway network in Xiaoshan District of Hangzhou City.The results show that the distribution traffic volume of the rebuilt OD is very close to the actual traffic volume,and the results of OD rebuild are more accurate than the general OD estimation under the same traffic volume conditions.