ESTIMATING AN ORIGIN-DESTINATION TABLE FOR U.S. IMPORTS OF WATERBORNE CONTAINERIZED FREIGHT

Abstract

U.S. imports of containerized freight have been growing at about 10% per year over the past decade and now exceed 18.5 million TEUs (twenty-foot equivalent units) per year. Container traffic is highly concentrated at a small number of ports, with approximately 88% of total containerized imports (measured in TEUs) entering through the 10 largest ports. Clearly, waterborne containerized imports are of vital economic concern to the United States. Given the growth rate of imports experienced at U.S. container ports, the concentration of traffic at a small number of sea ports, and the vulnerability of some of these seaports to natural hazards, it is important to have an accurate understanding of the flow of containers from their origin country through U.S. seaports to their final destination in the United States, so that investments in port capacity and other transportation infrastructure can be made consistent with the needs generated by this traffic. This paper develops an optimization model to synthesize the PIERS international trade data, the Carload Waybill data available from the Surface Transportation Board, and economic data into an estimate of an origin-destination table for the number of containers (measured in TEUs) that are shipped from foreign countries to aggregations of Bureau of Economic Analysis (BEA) economic areas in the United States.