OD Matrix Estimation for Urban Expressway

Abstract OD information of urban expressway is the basis of analyzing the traffic operation and performance. A proper OD estimation method is capable of reducing the traffic surveys pressure and avoid traffic jams during survey and unreal OD information. This paper proposed a systematic method of OD estimation including traffic zone division in the form of the entrance and exit ramps of one direction on expressway, and established the seed OD matrix of high quality using the Gravity and Frator method. It estimated the OD matrix in the OD estimation module in TransCAD software, which was applied in the Inner Ring Road in Guangzhou city. The results showed that the relative errors of the traffic volumes on the links and ramps, the average trip distance and the traffic mileage are small with the seed OD matrix calculation and OD matrix estimation, which manifests that the estimated OD matrix is accurate and reliable and the proposed method is appropriate for the urban expressway traffic analysis.