Rail transit is the sum of commuter rail, heavy rail, and light rail. In several large urban areas, Amtrak and commuter rail stations are shared. Starting in 2001, stations serving the Alaska Railroad are included in the rail transit total.
Rail transit data for 2002 and later years include both directly operated and purchased transit services. Prior to 2002, data include directly operated services only.
1984-98: Amtrak, Amtrak Annual Report, Statistical Appendix (Washington, DC: Annual Issues).
1999-2010: Amtrak, Annual Report (Washington, DC: Annual Issues), p. 67 and similar pages in previous editions, available at http://www.amtrak.com/servlet/ContentServer?c=Page&pagename=am%2FLayout&cid=1241245669222 as of Nov. 2, 2011.
U.S. Department of Transportation, Federal Transit Administration, National Transit Database (Washington, DC: Annual Issues), table 21, and similar table in earlier editions, available at http://www.ntdprogram.gov/ntdprogram/data.htm as of Nov. 2, 2011.