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",,,