"TRB's National Cooperative Freight Research Program (NCFRP) Report 26: Guidebook for Developing Subnational Commodity Flow Data explores how state departments of transportation and other subnational agencies can obtain and compile commodity flow data. The Guidebook contains descriptions of existing public and private commodity flow data; standard procedures for compiling local, regional, state, and corridor databases from these commodity flow data sources; procedures and methodologies for conducting subnational commodity flow surveys and studies; and methods for using commodity flow data in local, regional, state, and corridor practice. In addition to the Guidebook, two subtask reports from NCFRP Project 20--Review of Subnational Commodity Flow Data Development Efforts and National Freight-Related Data Sets and Demonstration of Application of Establishment Survey--are available only in electronic format."--Publisher's description.