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20 loaded from shore facilities directly into bunkers of vessels for destination states are designated "00" since the flow is purely fuel; and insignificant amounts of government materials (less international. In addition, records show domestic shipments than 100 tons) moved on government-owned equipment in classified as international flows. These state-to-state flows are support of Corps projects. Foreign commerce data are fur- labeled starting with the point of entry or exit into the United nished to the Corps of Engineers by the Bureau of the Census States shown respectively as the origin or destination for under a working arrangement sponsored by the Office of reporting purposes. The international origin or destination Management and Budget. also is given. The STCC13-Petro file contains international pipeline flows in tons for 1998, 2010, and 2020. These flows are not Freight Analysis Framework Commodity Database usually part of statewide freight forecasting models. FAF, described in Section 8.5, produced a Commodity A summary of the contents of the FAF Commodity Flow Flow Database (CFD) that provides O-D information on Databases is shown in Table 5.1. The database can be commodity flows by mode for the years 1998, 2010, and 2020. obtained from the Federal Highway Administration at http:// These flows, given in tons, are organized by commodity and mode. The CFD is divided into domestic flows (state-to- state) and international flows. The data are available in both 5.2 Flow Conversion Microsoft Access 2000 (*.mdb) format and tab-delimited text (*.txt) format, the latter suitable for importing into a Flow data available or forecast using the methods in this Microsoft Excel spreadsheet. A set of lookup tables of the Toolkit may require conversion into other units for process- STCC Commodity and Federal Information Processing Sys- ing or analysis. Commodity flow data, reported and forecast tem (FIPS) codes for states also is provided. Separate tables in terms of annual tons, is typically converted into vehicles are provided for domestic, international, international air, and economic value. Vehicle conversion is generally done for and petroleum flows. commodity flow by trucks, since freight trucks are assigned For domestic flows, the Federal Highway Administration together with automobiles and other trucks as daily trip provides a single file that contains state-to-state freight flows tables. by commodity and mode for 1998, 2010, and 2020. Figure 5.3 illustrates the Microsoft Access data format. The first and sec- Tons to Vehicles ond columns indicate a state freight flow from origin "05" to destination "06." The FIPS reference table translates this to a The assignment model component for truck freight on flow from Arkansas to California. The next three columns highways, described in Section 4.0, is most often calculated in indicate rail flows of 4,800 tons in 1998, 5,772 tons in 2010, terms of daily truck trips. For the truck model class with fore- and 5,930 tons in 2020. The sixth column labeled STC corre- casts in those units, this is obviously a straightforward proce- sponds to the STCC reference table. In this case, "01" corre- dure. For commodity models that forecast flow in annual tons sponds to farm products. per year up to and through mode split, a conversion process is Note that the O-D pair in the database is not unique. The required. The Indiana case study uses the Carload Waybill rail freight flow of farm products is not the only movement sample to relate tons shipped per carload to develop factors to from Arkansas to California. Rather, many records for all convert from annual tons to rail carloads and then applies a commodities by modes between Arkansas and California can factor relating the volume of a rail car to the volume of a com- be found later in the table. bination truck trailer to develop tons per truck trailer. More The International database file represents freight flows of commonly, the Vehicle Inventory and Use Survey (VIUS)from international origin or destination, by commodity and mode the Economic Census is used to develop these factors. for 1998, 2010, and 2020. It adds the international region of origin or destination (Mexico, Canada, Europe, Latin Amer- Vehicle Inventory and Usage Survey ica, Asia, and Rest of World) to the database and indicates whether the freight is exported or imported. The actual state VIUS, conducted every five years as part of the U.S. Eco- in which the freight enters or exits the United States is nomic Census, provides detailed information on the physical reported as the origin or destination. and operational characteristics of the nation's truck popula- The International Air dataset contains freight by air only, tion. VIUS is based on a sample of approximately 150,000 from international origins or destinations. The beginning trucks, or 2,000 trucks per state. From this sample, state and records in the file contain records on foreign air shipments national estimates are produced. Operational characteristics, that do not have a U.S. destination or origin. These are which are of particular interest to forecasters, include major labeled foreign in the Direction column. Both the origin and use, products carried, annual and lifetime miles, area of

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21 Figure 5.3. Freight analysis framework domestic flows database in Microsoft Access. operation, miles per gallon, operator classification, and haz- The weighted annual mileage for each VIUS product car- ardous materials transported. The sample also includes ried distance class can be calculated for each record in a state expansion factors for each record. VIUS uses product classes database. That mileage can be multiplied by the average pay- similar to the commodity classes used in the CFS or load for that record to obtain the weighted annual pound- TRANSEARCH/FAF. It records the percentage of the miles miles by product class. The weighted annual pound-miles that a truck carries certain products, equipment, materials, and the weighted annual miles can be summed over all etc. "No Load" is treated by VIUS as a separate product cate- records by product class. The average payload for each com- gory. The VIUS survey also includes buses and service trucks. modity can be obtained by dividing the average annual Certain VIUS product categories, such as passengers carried, pound-miles by the average annual miles. This payload does do not correspond to the freight model commodity classes. A not include the percentage of mile that a truck travels while correspondence between the VIUS product classes and the empty. This percentage by commodity also can be calculated more common commodity classes can be easily developed from the VIUS "No Load" product class. The factor to be based on the definition of each classification scheme. used to covert from annual tonnage to annual trucks could Table 5.1. Contents of commodity flow datasets. Database File Name Content Domestic Flows Domestic State-to-state flows By commodity By mode By year (1998, 2010, 2020) International Flows International International flows (by state origin or destination) By commodity By mode By year (1998, 2010, 2020) International Flows International Air International flows By air By year (1998, 2010, 2020) By state origin or destination Foreign shipments only Domestic shipments only International Flows STCC13-Petro International flows of crude petro/natural gas (by state origin or destination) By pipeline (other) By year (1998, 2010, 2020)

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22 account for both the average payload and the percentage of Commodity Flow Survey empty trucks in each commodity. The 1997 CFS reports commodities by SCTG code and con- The 1997 VIUS is available on CD-ROM from the tains both value and tonnage data for each commodity by state. U.S Census Bureau at This information can be used to develop conversion tables of 97vehinv.html. value per ton by SCTG commodity. Values by commodity by mode can be used to account for differences in the mix of com- Tons to Value modities at the SCTG two-digit level by mode. This is useful Converting tons per year to dollars shipped is useful in eco- when, for example, high value commodities that only can be nomic analysis or to account for forecasting methods that identified at the SCTG three- or four-digit level move prefer- consider the value of the freight being shipped. These con- entially by air and distort the overall average calculations of version factors can be obtained from the CFS. value at the two-digit level. Table 5.2 shows the values from the Table 5.2. Value per ton by commodity and mode for the state of California. Area California SCTG Electronic and other electrical equipment and components and office equipment Characteristic Value ($ million) Tons (000) Value per Ton ($) Item Data Symbol Data Symbol Mode All modes $ 206,731 5,057 $ 40,880 Single modes $ 132,620 4,274 $ 31,029 Truck $ 109,862 4,050 $ 27,126 For-hire truck $ 78,259 2,796 $ 27,990 Private truck $ 29,664 1,129 $ 26,275 Rail $ 414 2 Water $ 53 2 Shallow draft 2 2 Great Lakes 1 1 Deep draft $ 53 2 Air (includes truck and air) $ 22,291 148 $ 150,615 Pipeline 2 2 Multiple modes $ 57,088 396 $ 144,162 Parcel, U.S. Postal Service or courier $ 56,595 383 $ 147,768 Truck and rail 2 2 Truck and water 2 2 Rail and water 1 1 Other multiple modes 1 1 Other and unknown modes $ 17,023 387 $ 43,987 Note: A symbol of 1 represents zero or less than one unit of measure. A symbol of 2 represents data that does not meet publication standards due to high sampling variability or other reasons.