Source: adapted from B. Hoyle and J. Smith (1998) "Transport and Development: Conceptual Frameworks", in B. Hoyle and R. Knowles, Modern Transport Geography, 2nd Edition, London: Wiley, p. 17.
Dimensions of Transport Geography
Since transport geography is a multidisciplinary field, it can be approached from several dimensions of inquiry: 
  • Economics. This dimension is concerned about mobility and its associated costs the costs, the financing, construction and the maintenance of transport modes and infrastructures. The performance of transport systems are often measured and justified by economic criteria such as profitability. This dimension also tries to evaluate the transport demand generated by different sectors of activity.
  • Engineering. Notably concerned by the construction and maintenance of transportation modes and infrastructures, which relies on technology and techniques related to materials sciences (civil engineering, mechanical engineering, etc.). A dominant aspect of transport supply is linked to engineering considerations.
  • Environment / Ecology. Concerned about the impacts of transportation on ecological systems such as the atmosphere, the hydrosphere and the ecosphere. It also considers a wide array of externalities such as noise and land use. Another dimension of this field involves the impacts of natural conditions, such as topography and climate, on the operation of transport systems.
  • History. Covers the evolution of transport networks in time and space by trying to identify specific conditions that have influenced the establishment of transport networks and the technological, economic and social environments that have produced transport systems.
  • Mathematics and Computer Science. Provide a set of tools and methods to manage information and to analyze transport related information. Most models applied to transport geography, such as spatial interaction models, are derived from mathematical methods. Operations research has considerably contributed to the field of transportation by offering a set of methods to optimize the distribution and scheduling of transportation resources.
  • Planning and Policy. The political dimension aims to plan and control the transportation system through several agents, their jurisdiction and their intervention strategies. It is mainly concerned about the processes and methods for the allocation of transportation resources within corporations and governments.
  • Sociology and Demography. Covers problems such as accidents, the behavior of drivers and other social aspects related to modal and spatial choice having an effect on the distance traveled. For instance, the social costs of car use impose burdens on health and safety systems (police, ambulance, trauma centers, road signs, etc.). Demographic attributes and changes such as the aging of the population are also linked with the evolution of transport system, the modes used and the level of services.
  • Technology. Not necessarily a field of study but a consideration of the impacts of technological change on transportation systems. It is mainly concerned about the efficiency of  infrastructures, modes and motive forces. Successive innovations have brought forward new distribution systems whereas others have became obsolete and disappeared.