Spatial representation in the social interaction potential metric: an analysis of scale and parameter sensitivity

The Social Interaction Potential metric measures urban structural constraints on social interaction opportunities of a metropolitan region based on the time-geographic concept of joint accessibility. The current implementation of the metric utilizes an interaction surface based on census tracts and the locations of their centroids. This has been shown to be a shortcoming, as the metric strongly depends on the scale of the zoning system in the region, making it difficult to compare the Social Interaction Potential metric between metropolitan regions. This research explored the role of spatial representation in the Social Interaction Potential metric, and identified a suitable representation that allows for error-free comparison between regions while retaining cost-effectiveness with respect to computational burden. We also reported on findings from an extensive sensitivity analysis investigating the Social Interaction Potential metric's input parameters such as a travel-flow congestion factor and the length of the allowable time-budget for social activities.