NOTES: For consistency, aviation passenger-miles of travel (pmt) includes air carrier aviation only, as general aviation pmt 2002 data were not available when this report was prepared. Total pmt excludes motorcycle pmt and results in some double counting of bus pmt.
To make it easier to compare data of differing magnitudes over time, the Bureau of Transportation Statistics divided the data for all years in each category (see corresponding tables in appendix B) by the initial year value and multiplied the result by 100.
SOURCES: Passenger-miles—U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics 2004, table 1-37, available at http://www.bts.gov/, as of January 2005. GDP—Based on chained 2000 dollar data from U.S. Department of Commerce (USDOC), Bureau of Economic Analysis, National Income and Product Accounts, summary GDP table, available at http://www.bea.doc.gov/, as of December 2004. Population—USDOC, U.S. Census Bureau, Statistical Abstract of the United States, Section 1: Population, table No. 2. Population: 1960 to 2003, available at http://www.census.gov/, as of May 2005.