There are several ways of studying future trends. First it is important to examine the immediate past history, then the present position and how it has arisen, and lastly the outlook projected from the present.
Another exercise is the comparison of a variety of forecasts of traffic, by destination, by route and by sector. Most forecasts are usually at least in part a projection of past trends, with quantitative (econometric) models or qualitative modification.
Whatever methods are chosen, a detailed study of the main agents for change is essential. These are:
1 Demand determinants.
2 Supply-side response through industry development, taking into account external and general economic factors.
3 Political philosophies and the ...