Transport: the tail that wags the dog
It is precisely because transport developments invariably come about for reasons that have nothing to do with tourism that it is notoriously difficult to predict far ahead how the transport tail is going to wag the tourism dog. This is abundantly evident in the inaccuracy of any transport-related predictions. As a result, serious transport forecasters seldom look more than ten years ahead. And the most far-sighted serious prediction of which I am aware is that for airport capacity in the south east of England - 30 years ahead, with any data beyond 20 years being viewed with extreme caution.