The Commodity Flow Survey (CFS) compiles a robust dataset of Hazardous Materials (hazmat) shipment estimates from hazardous materials shippers. These data allow for the identification of hazmat flows and the quantification of exposurethe risk proportionate to the level of activityby mode of transportation. Policy development, the rule-making process, and program planning use CFS Hazmat data, which is the only publicly available source of hazmat flow data for the highway and air modes.
The 2007 CFS increased its sample of hazmat shippers (also called "oversampling"). Because of this oversampling, hazmat records comprised 5.6 percent of all CFS records in 2007; up from 4.9 percent in 2002 (percentages are prior to weighting of the data).
In 2007, the Nation's transportation system carried 2.2 billion tons of hazmat worth $1.4 trillion accounting for 323 billion ton-miles (see Table A-3: Hazardous Material Shipment Characteristics by Hazard Class).1
Over half of hazmat tonnage is transported by the highway mode. The 2007 CFS recorded over 1.2 billion tons of hazmat transported 104 billion ton-miles over our Nation's highways. Private trucking carried 32 percent and for-hire trucking carried 22 percent of hazmat tonnage (Table A-4: Hazardous v. Nonhazardous Material Shipment Characteristics by Mode of Transportation).
Industries that shipped the most hazmat tonnage in 2007 were Petroleum and Coal Products Manufacturing (NAICS 324)with 931 million tons, and Petroleum and Petroleum Products Merchant Wholesalers (NAICS 4247)with 804 million tons (Table A-5: Hazardous Material Shipment Characteristics for Selected NAICS Code).
Most of the hazardous materials transported are Flammable Liquids (Hazard Class 3). Of the 2.2 billion tons of hazmat shipped overall, 1.8 billion tons were flammable liquids, consisting primarily of refined petroleum products. This class also accounted for 182 billion of the 323 billion total hazmat ton-miles generated. Single-mode trucking carried more than 45 percent of tonnage for each Hazard Class except Class 6 (Toxic Materials and Infectious Substances), which had roughly half of its tonnage transported by rail.
The hazmat category of "Toxic by Inhalation" (TIH) includes TIH gases and volatile liquids that are toxic when inhaled. In 2007, shippers sent 27 million tons of TIH materials, which accounted for 10 billion ton-miles.
Packing Group I designates materials that have the most rigorous standards of preparation for transport.2 In 2007, shippers sent 586 million tons of Packing Group I materials, generating 72 billion ton-miles.
The map in figure A-6, Hazardous Material Tonnage by Originating State, 2007, shows the amount of hazmat shipments in tons by State of origin. In 2007, Texas was the leading State with 499.5 million tons (accounting for 22.4 percent of the U.S. total), followed by Louisiana's 221 million tons (9.9 percent), and then California's 199.7 million tons (9.0 percent).
BTS sponsored a Commodity Flow Survey (CFS) workshop held on November 16, 2010, at the Transportation Research Board's Keck Center in Washington, D.C. The workshop facilitated discussions of data uses and needs among Commodity Flow Survey users as well as derivative products and applications, such as the Freight Analysis Framework (FAF), and served as a forum on potential future improvements.
The workshop covered the impacts of changes in transportation services and practices on the effectiveness of the CFS, and improvements and methodological changes that may be implemented in the near term to enhance the survey.
The panelists discussed the Content and Uses of the CFS; the CFS Scope, Classification, and Geography; and the CFS Product Tools and Functionality in three sessions. In addition, attendees presented 13 posters on a range of subjects related to the CFS, such as community, freight, and highway project planning.
For the latest data sets and reports, please visit the CFS program page at http://www.bts.gov/publications/commodity_flow_survey/.
1 By definition, a ton-mile is the shipment weight multiplied by the mileage traveled by the shipment. Ton-miles represent 1 ton of freight shipped for 1 mile. It is the primary physical measure of freight transportation. By combining the weight (tons) and distance of shipment (miles) into one measurement, ton-miles are useful for transportation data analysis.
2 The Packing Group designation reflects the level of hazard associated with the material being shipped.