The primary objective of the highway freight capacity analysis is to develop a policy tool for analyzing potential freight-related policy and examining the sufficiency of capacity of the transportation system in meeting forecast freight demand. Developing a framework for policy analysis relating to the highway capacity for freight transportation is multi-dimensional and challenging. The U.S. freight system is complex and diverse in terms of the spatial and temporal distribution of freight generation activities and movement.
The critical elements of the national-level freight transportation modeling process include the establishment of the network and freight data preparation. Procedures for converting commodity flows into truck trips are not well developed. Inconsistencies in traffic data collection and reporting formats among states pose challenges in developing a comprehensive baseline truck traffic data base for national-level freight analysis.
It is important to take into account the specific characteristics of truck traffic in adapting and applying existing transport demand modeling techniques. The use of TransCAD based GIS-Transportation application software for the analyses is not only efficient but also facilitates communication of outputs of the analysis to policy makers. The truck flow maps and other thematic maps, for example, provide visual presentations of the volume and spatial variation of freight traffic. The outputs of the analyses can be expected to assist policy makers in evaluating improvement and policy options that affect freight transportation.
The link-specific freight flow data and the performance measures developed under this project should help FHWA freight policymakers to identify freight-related network problems and forecast the improvement or preservation needs of the national highway system to maintain the efficiency of freight movement. The database is available through the FHWA website @ http://ops.fhwa.dot.gov/freight/freight_analysis/faf/index.htm
