This paper discusses a number of theoretical points related to the investigation of travel characteristics, with particular reference to the elderly. It starts by discussing a number of basic terms, pointing out their relationships and discussing their implications for research and policy. It is argued that, in the context of social policy on transport, travel should be investigated in the light of the activities to which it gives access, rather than as a phenomenon in its own right. Another important aspect of travel is the way in which it is constrained, through the limitations of the person or of the transport system. The difficulties of isolating the effects of travel constraints are pointed out. The paper concludes with a discussion of some ways in which "need" may be defined and assessed.
Abstract