Abstract
The Freight Analysis Framework (FAF), a nation-wide commodity-based freight flow database, is the only publicly available data source that provides a comprehensive resource of national freight movement data. The FAF estimates origin-destination (O-D) commodity flows between states, sub-state regions, and major international gateways. Recently, there are emerging needs of the FAF data at a more detailed geographical level than is presently available. Taking the agricultural commodities as an example, this study presents a disaggregation approach that aims at disaggregating the existing zone-level commodity flows to county-level commodity flows. With limited agricultural commodity data and statistics, the disaggregation process includes three major steps: (1) estimation of county-level agricultural commodity production at origins, (2) estimation of county-level agricultural commodity attraction to destinations, and (3) estimation of county-level origin-destination agricultural commodity flows. The disaggregation process is applied to major farm-based agricultural products considered in the FAF. This paper discusses the process and illustrates the resulting geographic distributions of county-level agricultural commodity production and attraction. A few examples of county-level flows between origins and destinations are also presented.