U.S. Freight transportation: origin and destination data (by urban area) for selected commodities.
This dataset also depicts the hypothetical risk levels (see map below) of urban and periurban forest areas in the contiguous United States to introductions of exotic insects based solely on the amount of urban and periurban forestland and the tonnage of three categories of imported goods from four world regions (rate of entry of exotic species is assumed to be proportional to the amount of tonnage). The selected imported goods are known to be pathways for the introduction of bark- and wood-infesting insects. Details on the approach followed to determine risk levels and to model the final destination of products are documented in the Journal of Economic Entomology 102 (1): 237-246 (PDF version).
