planning what transport infrastructure to provide, and where, is a complex task for policy makers. a key feature of transport is that it is a derived demand; that is, people or freight do not travel for the sake of making a journey, they travel for some other reason (for example, in the case of people to go on holiday or to go on a business trip; in the case of freight to go to a market or another factory for further processing). the case below illustrates the range of range of issues to be considered in planning transport infrastructure