|Public road lanesa||8,251,865||8,567,618|
|Gas transmission and gathering||311,391||325,174|
|Class I freight railroad||97,817||95,387|
aMeasured in lane-miles. bMeasured in directional route-miles. cEstimated length of domestic waterways.
Sources: Highway, Rail, Transit, Water–U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics, tables 1-1, 1-6, and 1-10, available at www.bts.gov as of October 2013. Pipeline–U.S. Department of Transportation, Pipeline and Hazardous Materials Administration, available at phmsa.dot.gov/pipeline/library/data-stats as of October 2013.