Goal Programming Approach to Allocate Freight Analysis Framework Mode Flow Data

Several methods have been proposed to disaggregate Freight Analysis Framework (FAF) commodity flows to zonal structures of greater geographical detail. This disaggregation is usually performed on the basis of explanatory variables related to the supply and demand of goods. This paper studied a complementary procedure to determine the mode splits of disaggregated FAF flows. A goal programming approach was proposed to allocate FAF mode flow data on the basis of mode-related variables. The formulated goal programming problem minimized the deviation between the mode flow decision variables and target mode flow values, subject to given FAF mode flow information. The use of mode split models was proposed to define the problem's target values. In a sample application of the procedure, a method to estimate aggregate mode split models with FAF data was discussed. Mode split models could be used by transportation organizations that did not have access to freight mode choice models to define the goal programming problem's target mode flow values. In addition, an optimization problem was formulated to account for FAF mode flow data in the disaggregation of total commodity flows. Last, validation procedures for FAF disaggregation and mode allocation results were discussed, and an example of a validation approach was presented.