Development of an Equity Metric for Infrastructure Service Performance Assessment

Infrastructure service outages are often disproportionately clustered among vulnerable population groups (e.g., low income) who are also often more adversely impacted by these outages due to limited resources. These inequities need to be reduced for community resilience's improvement. Equity is increasingly considered an integral part of risk-based decision-making. There is no consensus on equity's definition within the infrastructure context, but equity is best characterized by five dimensions: recognitional, distributional, restorative, procedural, and transgenerational. Few metrics currently accommodate equity robustly, particularly the restorative dimension. Theil's T-derived infrastructure metrics are presented to assess infrastructure service performance inequities for both the restorative and distributional equity paradigms, which can ultimately support infrastructure intervention decisions (e.g., retrofit, system operation) to robustly consider equity. The restorative paradigm necessitates the assessment of differences between distinct groups, whereas the distributional paradigm necessitates an equality assessment across the entire population. The metrics are derived for two infrastructure service performance quality measures represented through robustness and vulnerability. The proposed metrics are implemented in a limited hypothetical electric distribution network to evaluate the metrics' capability to detect degrees of inequity introduced into the system through varying nodal vulnerability scenarios. The results confirm the metrics' ability to benchmark inequity and represent an approach for equity's quantification alongside other factors in risk-based decision-making, which will be integral to supporting equity in future infrastructure decisions.