A MULTI-MODAL SUPPLY-DEMAND EQUILIBRIUM MODEL FOR PREDICTING INTERCITY FREIGHT FLOWS

This paper presents a new supply-demand equilibrium approach to intercity freight transportation system modeling in which the supply side represents carrier behavior and the demand side represents shipper behavior. Shipper decisions considered include choice of destination, mode, carrier for pure modes and transfer points for combined modes. Carriers take routing decisions over a multi-modal, multi-product and multi-operator network. A new mathematical formulation is proposed to find consistent equilibrium solutions for modal origin-destination shipments, network flows and levels of service. Necessary conditions are deduced to show that the solutions obtained, from the mathematical formulations proposed, satisfy the behavior principles assumed in each case. It is shown that two conditions are required to obtain consistent supply-demand equilibrium solutions: fares charged by carriers must be consistent with operating costs, and carrier network routing decisions cannot be taken without consideration of the effect that they have on shipper costs. Sufficient conditions for the existence and uniqueness of solutions to diagonalized versions of the mathematical problem formulated are deduced. A solution approach is proposed to obtain equilibrium flows. A sample application demonstrates the feasibility of application and illustrates the characteristics of the outputs obtained and their relation with the model formulation.

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  • English

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  • Accession Number: 00960759
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 11 2003 12:00AM