Seasonally adjusted, yearly averages
NOTE: These results, based on ongoing research, are preliminary. The Travel Time Variability Index is based on the standard deviation of actual travel time.
SOURCES: Data for scheduled and actual air travel times— U.S. Department of Transportation
(USDOT), Bureau of Transportation Statistics (BTS), calculations based on Airline Service Quality
Performance data, March 2004.
Flight operations—USDOT, BTS, Airline Market and Segment (T-100) data, March 2004.