Transportation Economic Trends
Transportation as an Economic Indicator:
Seasonally-adjusted transportation data
Seasonal adjustment is the process of estimating and removing movement in a time series caused by regular seasonal variation in activity, e.g., an increase in air travel during summer months. Seasonal movement makes it difficult to see underlying changes in the data. Monthly shifts in data as well as short and long-term trends can be best seen through seasonally-adjusted data. This page features transportation data series seasonally-adjusted by the Bureau of Transportation Statistics. BTS uses seasonally-adjusted data in the Transportation Services Index.