Transportation Department issues January airline traffic data

Based on findings from the U.S. Transportation Department's (USDOT)  Bureau of Transportation Statistics (BTS) showing the nation’s airlines’ scheduled service load factor – a measure of the use of airline capacity – was unchanged from December 2014 to January 2015, as seasonally adjusted.

January’s figure of 83 percent came in slightly under the record high of 84.4 percent set in January 2014. The figures apply to both domestic and international flight data. Findings were compiled by the office of the Assistant Secretary for Research and Technology at USDOT.

Load factor refers to the measure of the use of aircraft capacity that compares the system use, measured in Revenue Passenger-Miles (RPMs) as a proportion of system capacity, measured in Available Seat-Miles (ASMs).

BTS looks at air travel data from two perspectives: seasonally adjusted, and unadjusted. Because transportation is highly seasonal, without adjustment, the data do not give an accurate picture of underlying changes in aviation passenger travel.

Seasonal adjustment of the data removes seasonal events that follow a regular pattern. Changes that are not due to seasons, such as a change in air travel resulting from economic conditions, become more readily apparent. Seasonally adjusted trends are for January 2000 to present.

The information is compiled from monthly reports filed with BTS by commercial U.S. air carriers detailing operations, passenger traffic and freight traffic. It includes data from 80 carriers as of April 7 for civilian U.S. carrier operations.

Data are subject to revision, and BTS has scheduled May 14 for the release of February traffic data.