1-1,
The Transportation Network: 2006,
Mode,Components
Highway,Public roads
(2005),"46,871 miles of Interstate highway"
,"115,502 miles of other National Highway System roads"
,"3,849,259 miles of other roads"
Air,Public-use airports
,"5,233 airports"
,Airports serving large certificated carriers (enplaned passengers)
,"26 large hub areasa (67 airports), 487 million passengers"
,"37 medium hub areas (62 airports), 141 million passengers"
,"67 small hub areas (83 airports), 53 million passengers"
,"924 nonhub areas (959 airports), 23 million passengers"
Rail,Miles of railroad operated
(2005),"95,664 miles by Class I freight railroads in the United Statesb"
,"15,388 miles by regional freight railroads"
,"29,197 miles by local freight railroads"
,"22,007 miles by Amtrak (passenger)c"
Urban transit,Directional route-milesd 
(2005),"Bus: 168,639e"
,Trolley bus: 429 
,"Commuter rail: 4,450"
,"Heavy rail: 1,601"
,"Light rail: 1,091"
,Stations 
,"Commuter rail: 1,164"
,"Heavy rail: 1,042"
,Light rail: 730
Water,"Navigable channels: 26,000 miles"
(2005),Ferry routes: 639 directional route-miles
,Commercial waterway facilitiesa
,Great Lakes: 600 deep-draft
,Great Lakes: 154 shallow-draft
,"Inland: 2,321 shallow-draft"
,"Ocean: 4,398 deep-draft"
,"Ocean: 1,926 shallow-draft"
,Locks: 257
Pipeline,Miles of oil pipe
(2005),"Crude lines: 60,043"
,"Product lines: 71,310"
,Miles of gas pipe
,"Transmission: 296,400"
,"Distribution: 1,117,800"
a See Glossary for definitions.   ,
"b There are also 1,368 miles of railroad operated within the U.S. Class I freight railroad system that are owned by Canadian railroads.",
c The Amtrak mileage includes the 745 miles of trackage it owns and route-miles operated on freight railroad tracks.   ,
d Directional route-miles includes only directly-operated service. Does not include contracted service.   ,
"e Includes directional route-miles on exclusive right-of-way, controlled right-of-way, and mixed traffic.",
"Sources: Various sources, as cited in USDOT, RITA, BTS, National Transportation Statistics, available at http://www.bts.gov; Association of American Railroads, Railroad Facts, 2006 (Washington, DC: 2006); USDOT, Federal Highway Administration, Highway Statistics 2005 (Washington, DC: 2006), table HM-18; Oil & Gas Journal, Sept. 11, 2006; USDOT, Federal Transit Administration, 2005 National Transit Summaries and Trends, tables 21, 23, and 24, available at http://www.ntdprogram.com/ntdprogram/pubs.htm; USDOT, RITA, BTS, “Airport Activity Statistics of Certificated Air Carriers, Summary Tables, 12 Months Ending Dec. 31, 2006,” 2006; U.S. Army Corps of Engineers, Institute for Water Resources, Navigation Data Center, The U.S. Waterway System Facts, February 2007 (Alexandria, VA: 2007).",