A multi-modal freight transportation model is presented, based on a digitized geographic network. A systematic analysis and decomposition of all the transport operations leads to the development of a virtual network where each virtual link corresponds to a specific operation, and all transportation modes and means are interlinked. Software, called NODUS, automatically generates the virtual network so that the model can be easily applied to large networks. The analytical structure of the links notation makes it simple to attach specific cost functions to each virtual link. The model is applied to the trans-European freight network for the transportation of wood products. Cost functions are built up for each operation by each mode/means combination. A detailed point-to-point origin-destination matrix, calibrated on Eurostat statistics, is generated by a Monte Carlo technique. The total transportation cost is then minimized with respect to the choices of routes, modes, and means. This provides estimations of transportation services demands as well as modal splits, to the extent that the 2 hypotheses of demand based on generalized cost minimization and market contestability are accepted. A sensitivity analysis on the relative road cost is made, providing measures of arc-elasticities.
Abstract