Maryland State Highway Administration
A number of statewide travel demand models have included freight as a separate component in analysis. Unlike passenger travel, freight has not gained equivalent attention because of lack of data and difficulties in modeling. In the current state of practice the most commonly used data for freight modeling is the Freight Analysis Framework (FAF) which is a summarized version of the Commodity Flow Survey. FAF data provides commodity flows between zones for seven freight modes. Since a large percentage of goods are carried by trucks, statewide models use FAF data to obtain flows between zones. In other words, the distribution of flow contains a fixed share of mode in a given analysis year. However, for some types of policy analysis this type of assumption might not hold true. For example, the opening of the Panama Canal might change the freight mode choice for certain commodities. This research presents a methodology to determine freight mode choice to use in the statewide travel demand modeling. By using logistic regression, commodity-specific “From,” “To,” and “Within MD” models were developed. Examples of each model are discussed in the report. Applications of the proposed methodology that could potentially be used in the Maryland Statewide Transportation Model (MSTM) were presented. The research results can be used to determine mode choice and to make broad level policy decisions on statewide freight travel.
Contact: Frederick Ducca