Spatial Form, Pattern and Interaction and the Environmental Impacts of Transportation

This figure presents two different urban spatial structures in terms of form, pattern and interaction. In the first case, the city is more transit oriented while in the second, the car dominates.

• Spatial form. Simply the spatial aspect of the city in terms of its extent. The first case is more centralized and compact with corridors shaping the urban form. The second case is grid-like with limited centrality. It is likely that in the first case the average commuting distance is shorter than in the second.
• Spatial pattern. The organization of the land use in terms of location. In the first case the pattern is zonal, somewhat radial, and concentrated. In the second case the pattern is highly fragmented and dispersed. It would be difficult to achieve agglomeration economies and economies of scale in transit in such an urban environment.
• Spatial interaction. The intensity of movements between spatial entities. In the first case interactions are oriented along major axes and have a high intensity that can be efficiently serviced by public transit. In the second case interactions have a random pattern and a low intensity.

It is quite obvious that the second city is likely to have far more environmental impacts attributed to land use, simply because of its spatial structure and the transportation demands such a spatial structure creates.