Using Aggregated Federal Data to Model Freight in a Medium-Size Community

The efficient movement of freight within and through a region is vital to its growth and economic development. Transportation planning involves the development of travel demand models to support a region’s infrastructure investment decisions, but modeling professionals face limitations in obtaining accurate freight data. This problem originates from issues with gathering and utilizing data that are at the appropriate granularity. Freight data at the local level are considered proprietary and companies are reluctant to share. One approach in overcoming this limitation is to use a nonproprietary, national freight flow database. However, the high level of aggregation of the national freight flow data presents challenges for determining freight movements at the substate level. The publicly available data have to be supplemented by local information to provide reliable transportation demand forecasts suitable for planning purposes. Investigating future freight flows requires a deep understanding of the economic and industrial base of a region. For Alabama, this includes major manufacturing industries, agriculture, logging, and mining. Retailing, wholesaling, and warehousing activity also creates freight traffic. The base year for the economic database is 2002, the year corresponding to the Freight Analysis Framework 2 (FAF2) and also when the U.S. Census Bureau surveyed industries for its series of state economic censuses.