|Light-duty highway vehicles||Air carrier, domestic||U.S. and foreign air carrier, international||Bus||Motorcycle||Transit||Intercity/ Amtrak|
NOTES: U.S. and foreign air carrier, international includes only scheduled flight segments to and from the United States. Light-duty highway vehicleincludes both short and long wheel base passenger cars, pickup trucks, vans, and sport utility vehicles (SUVs). Bus and demand response are included in both Bus and Transit, which results in some double counting. Amtrak does not include contract commuter passenger miles. The data in table above may not be consistent with other sources, particularly data that are revised on an irregular or frequent basis. Different vehicle occupancy rates were used to estimate passenger miles for Light-duty highway vehicles and Bus beginning with 2009. Nationwide travel data for walking and biking are not collected on an annual basis.
SOURCES: U.S. foreign air carrier, international: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, Scheduled Passenger Data Tool, available at http://www.transtats.bts.gov as of April 2016. All other categories: Various sources as cited in U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics, table 1-40, available at http://www.bts.gov/publications/national_transportation_statistics/ as of April 2016.