Estimating Multimodal OD Matrix from Mode Specific OD Matrices

In most case, freight demand data from shipper-based survey are aggregated and released in terms of mode specific O/D matrices. This makes them less useful for multimodal freight modeling because only with mode specific O/D matrices mode choice modeling cannot be applied. The objectives of this paper are to propose an algorithm which estimates a multimodal O/D matrix only using mode specific O/D matrices and to test the developed algorithm in terms of the solution quality and applicability for the real-world problem. The proposed model was tested on a test bed network. Results show the proposed model is able to estimate a multimodal matrix with an acceptable accuracy. In addition, the assigned link flows from the estimated multimodal O/D matrix were much closer to those from the real multimodal O/D matrix, compared to those from the simple sum of the mode specific O/D matrices.