Efficient spatial interaction: attainable reductions in metropolitan average trip length

We consider the intrinsic levels of spatial interaction necessitated by current North American urban spatial structure and investigate the potential for reducing average commuting trip lengths. In this paper, we use a doubly constrained spatial interaction model to generate critical parametric values which are then used to calculate the effort needed to reduce average trip length by a fixed target for each urban area. The measure of effort is defined as the degree of difficulty to achieve commuting and fuel consumption goals, and compared across a set of 26 US cities. Since the urban structure varies spatially, it is harder for some cities than others to reach a given level of reduced energy consumption.