Table 1: Data Sources for the Transportation Services Index
| Mode | Source | Measure | |
|---|---|---|---|
| Freight | Trucking | American Trucking Associations | Index of tonnage |
| Air | BTS and carrier websites | Freight of ton-miles | |
| Rail | Association of American Railroads | Carloads & Intermodal units | |
| Federal Railroad Administration | Quarterly ton-miles | ||
| Water | U.S. Army Corps of Engineers | Tons | |
| Pipeline | Energy Information Administration | Thousands of barrels, billion cubic feet | |
| Passenger | Air | BTS and carrier websites | Revenue passenger-miles |
| Rail | Federal Railroad Administration | Revenue passenger-miles | |
| Transit | American Public Transportation Association | Unlinked trips | |
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, 2007
Updated: Sunday, May 21, 2017