7.0 COMPILATION OF PROVISIONAL DATABASES
7.1 Introduction
The overall goal of the provisional estimates is to provide the latest updates of commodity – O-D movements that would serve as a source of data for practitioners in economic development, transportation planning, and transportation infrastructure analysis. This chapter describes the steps involved in compiling the databases from the individual modal estimates described in the preceding chapters.
7.2 Provisional Databases
Having developed the estimates for each mode, the next step was to compile databases as depicted in Figure 7-1 and described below. These databases were compiled using Structured Query Language (SQL) queries developed specifically for this purpose. The database structure is consistent with the 2002 FAF database. Each record contains FAF zone of origin, FAF zone of destination, port of entry or exit (which applies only to export and import flows), type of commodity, mode of transportation, value in millions of dollars, and tons in thousands of short ton.
Figure 7-1. Provisional O-D Databases
- Domestic, comprising all movements with origins and destinations within the U.S. by all modes – highway, rail, water, pipeline, and air.
- Land border, including international movements, i.e., import and export via land border crossings between the U.S. and Mexico, and between the U.S. and Canada. This includes movements by truck and rail only.
- Sea, including all international movements, i.e., imports and exports via the seaports between U.S. and other countries. This includes multimodal movements that include truck, rail, pipeline, and water.
- Air, exclusively for international air cargo covering import and export via airports.
In addition to the databases, state and national summaries were prepared. These summaries present the total volumes and values of commodities originating from or destined to each state by mode as well as the percentages by mode of the total shipments for the given year for that state.