This report uses trade data from many sources: the Census Bureau's U.S. Merchandise Trade data, the Bureau of Economic Analysis' (BEA) balance of payments trade data, the Bureau of Transportation Statistics' (BTS) Transborder Surface Freight Data, and the U.S. Customs Service's border-crossing data.
Data on U.S. total international merchandise trade and trade by air and water modes are from the Census Bureau's Foreign Trade Division. U.S. total merchandise trade data in inflation-adjusted terms are from BEA. These inflation-adjusted data, however, are not available for imports and exports at the country level and for mode of transportation and type of commodities. Consequently, this report uses current dollar data for most of the trade discussions. Data on merchandise trade transported by all land modes, including data on commodity groups, and origins and destinations of the trade flows, are from the BTS Transborder Surface Freight Data.
The report also uses U.S. Customs Service data on trucks crossing into the United States from Canada and Mexico. These data represent the number of truck crossings into the United States, including both loaded and unloaded trucks. The data do not count individual unique vehicles. For example, one truck may cross the border multiple times in one day. Each crossing would be counted. The data also do not provide information on the goods carried by the trucks or the U.S. destinations.
Traded goods usually move by more than one mode of transportation from origin to final destination. In U.S. trade statistics, the export mode of transportation is the mode used when the U.S. international border is crossed. For imports, the mode of transportation is the last mode used when the freight was transported to the U.S. port of clearance or entry. The available trade data do not distinguish goods moved by intermodal combinations.