|U.S. air carrier, domestic||486,506||575,613|
|Light duty vehiclea||*||3,644,971|
*2001 highway data are omitted because they are not comparable to 2011 data due to a change in vehicle occupancy rates derived from National Household Travel Surveys.
aIncludes passenger cars, light trucks, vans, and sport utility vehicles. bMeasured in revenue passenger miles.
Source: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics, table 1-40, available at www.bts.gov as of October 2013.