The application of geographic information systems in transportation dates from the very earliest. GIS is about many things, but one consistent theme in its development has been the economies of scale that derive from integrating a wide range of processing functions around a well-defined data structure representing one or more particular classes of geographic data.

Transportation professionals the world over have discovered and embraced GIS as an important tool in managing, planning, evaluating, and maintaining transportation systems.

Road transport investments over the years have contributed a great deal to shaping urban growth and the forms of settlement. Their importance to the economic development of cities and regions, combined with issues of environment, congestion, and safety, has seen the planning and management of transportation systems high on government agendas worldwide.

The adverse environmental effects of road transport include air pollution, pollution of natural drainage systems, noise disturbance, and extensive energy consumption. It appears likely that environmental conditions will worsen in most urban areas in the immediate future with increases in both the number of motor vehicles and the mean distance traveled by each vehicle. There are considerable advantages in incorporating environmental modeling directly into the transport planning processes to enable the assessment of the environmental effects of different transport proposals and scenarios simultaneously with the assessment of their traffic effects.