||The study of the role of transport in geography, including the provision of transport systems, the use of those systems for the movement of people and goods, and the relationships between transport and other geographical phenomena.
Nineteenth-century geographers (e.g. F. Ratzel and A. Hettner) recognized the importance of transport as providing features of the landscape and as an agent of geographic change. In the early twentieth century leading French geographers (e.g. P. Vidal de la Blache and J. Brunhes) developed the geographical study of transport as part of the \'geography of circulation\', which studied not only the permanent landscape features associated with transport but also the transient movements of goods and people. The sub-discipline developed little until the 1950s, when studies of individual transport modes were initiated (ports, airports and railways). Then, in the 1960s North American geographers led by E.L. Ullman, W.L. Garrison, E.J. Taaffe and others, demonstrated the applicabiliity of quantitative techniques for transport studies. As a result there was a rapid expansion of studies in transport geography (often with direct or indirect planning applications). But this whole approach came under critique because in its attachment to quantitative methods and positivism it seemed to emphasize spatial patterns and spatial associations at the expense of a fuller theoretically based understanding of transport phenomena in a broader economic and social perspective.
The first and most persistent feature of transport geography has nevertheless been the study of transport phenomena in their own right. Five categories of work can be identified:
network studies attempt to describe the geographical pattern of transport networks (roads, railways, canals, etc.), and to explain these patterns either at the level of the whole network or by reference to individual links, including an account of how these patterns have changed over time by the growth and decay of networks.
Studies of transport nodes and terminals have concentrated chiefly on ports and airports, describing not only the morphology of individual facilities and their evolution over time, but also of whole systems of competing ports and airports. Some authors have attempted to systematize these studies in the form of idealized sequences or models.
Studies of the provision of scheduled services (by train, bus and air) complement the study of physical networks and terminals. Some of the descriptive studies use the same concepts and techniques as are applied to networks, but more successful measures incorporate reference to frequency of scheduled services in time as well as their spatial pattern. Recent studies have focused especially on the changes in patterns occasioned by the trend toward national and international deregulation. In all this work attention also needs to be paid to the mobility problems of those (in both rural and urban areas) who are dependent upon scheduled services, and the inequities between them and those who have access to private transport.
Studies of the movement of commodities have often been hindered by the absence of reliable and complete data, but where such data are available techniques (including factor analysis) have been developed to identify the distinctive structures within a complex set of flows (for example, the existence of hierarchies and subsystems). Explanations in terms of the geography of places have often used Ullman\'s bases for spatial interaction, while operational models have used been based upon linear programming and gravity models. Attention has also been paid to the issue of modal split (see transportation choice models). In recent years there has been a greater emphasis on the link between commodity flows and the organizational and behavioural characteristics of the commercial corporations as the initiators and agents of commodity movements.
The movement of people is studied at all geographical scales (within regions, between regions, and internationally). Once again complete and accurate data sets are difficult to collect, especially where large numbers of trips are made by private transport. Early descriptive studies have now largely been replaced by analytical or explanatory studies which attempt to account: first, for the number of movements originating in or terminating in a geographical area; second, for the levels of flow between areas; and third, for the allocation of these trips between competing modes. Earlier studies used aggregate travel models, the most successful of which were gravity models but other models (e.g. intervening opportunities) have their champions. From the 1980s onwards criticisms of the weak behavioural basis of such models led to an increased interest in various transportation choice models in which the behaviour of individuals is related to the perceived utility of alternative destinations.
A second common theme in transport geography is the role of transport as an agent or facilitator of geographic change. The geographical pattern of transport networks can often be correlated with urban growth and the location of manufacturing and service industry. Such spatial associations provide casual evidence that transport changes induce geographic change. But attempts to verify this claim stumble over two problems. The first is circular causation: although transport developments can lead to urban growth, urban growth itself may be the cause of transport expansion. The second is that the transport induced changes are often inextricably linked to concurrent changes induced by other causes.
The third area of interest has become more dominant in the 1990s. It is increasingly evident that the transport sector is a major consumer of energy and source of atmospheric pollution. The emission of hydrocarbons, additives, the products of the combustion of fossil fuels (particulates, oxides of nitrogen, carbon dioxide) has raised questions about the long-term sustainability of current transport systems, and two consequential problems for geography. First, if the use of transport has to be reduced for environmental reasons what new geographical patterns will emerge? Conversely, what new geographical patterns of economic and social activity, and what new patterns of transport provision will best facilitate such a reduction?
All these central concerns of transport geography have potential importance for transport planning: it is therefore unsurprising that transport geography has forged close links with the cognate of transport planning and traffic engineering.Â (AMH)
Suggested Reading Eliot Hurst, M.E ., ed., 1974: Transportation geography: comments and readings. New York: McGraw-Hill.Â Hanson, S., ed., 1986: The geography of urban transportation. New York: Guilford.Â Hanson, S. 1998: Off the road? Reflections on transportation geography in the information age. Geoforum 6: 241-9.Â Hoyle, B.S. and Knowles, R.D. 1992: Modern transport geography. London: Belhaven; Journal of Transport Geography 1993. Exeter: Elsevier Science.Â McKinnon, A.C. 1989: Physical distribution systems. London: Routledge.Â White, P. 1995: Public transport, 3rd edn. London: UCLPress.