a For-hire transportation includes for-hire air, rail, truck, water, and pipeline transportation; transit and ground passenger transportation, including State and local government passenger transit; sightseeing transportation; transportation supportive services; courier and messenger services; and warehousing and storage.
b "Other" consists of government enterprises (except State and local government passenger transit) and other I-O special industries. For a description of I-O special industries, see: Ann M. Lawson et al., "Benchmark Input-Output Accounts for the U.S. Economy, 1992: Make, Use, and Supplementary Tables," Survey of Current Business, 1997, 77(11), pp. 46-47.
c In-house transportation consists of the services provided by non-transportation industries for their use. It includes privately owned and operated vehicles of all body types, used primarily on public rights of way, and the supportive services to store, maintain, and operate those vehicles.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics.