KEY: U = data are not available.
a Locomotives used in Amtrak intercity passenger services are not included.
b Full-size buses have more than 35 seats; Mid-size buses have 25-35 seats; Small buses have fewer than 25 seats.
All data, except full-size, mid-size, small, and articulated transit bus:
1985-14: U.S. Department of Transportation, Federal Transit Administration, National Transit Database (Washington, DC: Annual reports), table 25 and similar tables in earlier editions, available at http://www.ntdprogram.gov/ntdprogram/ as of May 5, 2016.
2015-16: U.S. Department of Transportation, Federal Transit Administration, National Transit Database, Vehicles (Washington, DC: Annual reports), available at https://www.transit.dot.gov/ntd/ as of Apr. 25, 2018.
Full-size, mid-size, small, and articulated transit bus:
1985-91: U.S. Department of Transportation, Federal Transit Administration, National Transit Database 1991 (Washington, DC: 1993), table 29 and similar tables in earlier editions.
1992-2013: Ibid., National Transit Summaries and Trends (Washington, DC: Annual reports), table 25, available at https://www.transit.dot.gov/ntd/annual-national-transit-summaries-and-tr... as of May 5, 2016.
