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Acknowledgments US Department of Transportation - BTS

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The data are from Railroad Facts, published annually by the Association <strong>of</strong> American Railroads (AAR). Figuresreported by AAR are based on 100-percent reporting by Class I railroads to the Surface <strong>Transportation</strong> Board (STB)via Schedule 700 <strong>of</strong> the R1 Annual Report. STB defines Class I railroads as having operating revenues at or above athreshold indexed to a base <strong>of</strong> $250 million (1991) and adjusted annually in concert with changes in the RailroadFreight Rate Index published by the Bureau <strong>of</strong> Labor Statistics. In 2000, the threshold for Class I railroads was$261.9 million. Declassification from Class I status occurs when a railroad falls below the applicable threshold forthree consecutive years. Although Class I railroads encompasses only 2 percent <strong>of</strong> the number <strong>of</strong> railroads in thecountry, they account for over 71 percent <strong>of</strong> the industry's mileage operated.TABLE 1-33. Age and Availability <strong>of</strong> Amtrak Locomotive and Car FleetsAmtrak maintains a computer database with a record <strong>of</strong> every locomotive and car it operates. For each vehicle thoserecords include the year built, its service status (operating or not on a daily basis), and location. These data should beconsidered very reliable.TABLE 1-34. U.S. Flag Vessels by Type and AgeThe data are from the U.S. Army Corps <strong>of</strong> Engineers (<strong>US</strong>ACE), Waterborne <strong>Transportation</strong> Lines <strong>of</strong> the United States(WTL<strong>US</strong>), annual issues. The WTL<strong>US</strong> database contains information on vessel operators and characteristics anddescriptions for all domestic vessel operations. Data are collected by the <strong>US</strong>ACE's Navigation Data Center, primarilythrough a survey <strong>of</strong> vessel operating companies. More than 3,000 surveys are sent to these companies and responserates are typically above 90 percent. However, a <strong>US</strong>ACE <strong>of</strong>ficial did report that less than 10 percent <strong>of</strong> the totalnumber <strong>of</strong> companies operating inland vessel fleets either did not receive and/or did not respond to the annualsurvey.TABLE 1-35. U.S. Vehicle-MilesTABLE 1-36. Roadway Vehicle-Miles Traveled (VMT) and VMT per Lane-Mile by Functional ClassTABLE 1-40. U.S. Passenger-MilesAir Carrier, Certificated, Domestic, All ServicesThe U.S. <strong>Department</strong> <strong>of</strong> <strong>Transportation</strong> (<strong>US</strong>DOT), the Bureau <strong>of</strong> <strong>Transportation</strong> Statistics, Office <strong>of</strong> AirlineInformation, reports aircraft revenue-miles and passenger-miles in its publication Air Traffic Statistics. These numbersare based on 100-percent reporting <strong>of</strong> passengers and trip length by large certificated air carriers. Minor errors arisefrom nonreporting but amount to less than 1 percent <strong>of</strong> all air carrier passenger-miles. The figures do not include datafor all airlines, such as most scheduled commuter airlines and all nonscheduled commuter airlines. These, if added,may raise total air passenger-miles by about 5 percent.General AviationPassenger-mile numbers for 1975 to present are calculated by adjusting the Interstate Commerce Commission's1974 figure for air passenger-miles by the percentage change in annual hours flown by general aviation aircraft aspublished in the <strong>US</strong>DOT, Federal Aviation Administration (FAA), FAA Statistical Handbook <strong>of</strong> Aviation. Numbers inthe handbook are based on the General Aviation and Air Taxi Survey (GAATA). In 1993, the GAATA stoppedincluding commuter aircraft. Commuter-miles collected before 1993 by the GAATA were, according to one FAA<strong>of</strong>ficial, woefully underreported. Therefore, problems with the estimate <strong>of</strong> general aviation aircraft include: a break inthe series between 1992 and 1993, a possible outdated factor used to calculate passenger-miles, and theclassification <strong>of</strong> commuter operations.HighwayHighway vehicle-miles <strong>of</strong> travel (vmt) are estimated using data from the Highway Performance Monitoring System(HPMS), a database maintained by FHWA that contains information on highway characteristics supplied by individualstates. Annual vmt by highway functional system is calculated as the product <strong>of</strong> the annual average daily traffic(AADT) along each highway section, the centerline length <strong>of</strong> each highway section, and the number <strong>of</strong> days in the

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