A new direct demand model of long-term forecasting air passengers and air transport movements at German airports

The German Aerospace Center (Deutsches Zentrum fur Luft- und Raumfahrt e.V., DLR) has developed and applied a classical model of forecasting the total number of air passengers and aircraft movements at German airports for many years. The model follows the four-step approach of forecasting the trip generation, spatial distribution and assignment to routes and aircraft movements. In recent years, it has become increasingly difficult to update and verify the model because of a lack of specific data. We have therefore developed a more versatile model, which directly forecasts the total number of air passengers and air transport movements at German airports. The forecast functions are co-integrated regression models, which have been econometrically estimated taking into account time series data from 1992 to 2015. The paper describes the model approaches and discusses the advantages and disadvantages of both the classical and new model approaches. The new model has been employed to estimate the effects of Brexit on traffic volume at German airports for the years 2016 to 2018.