Indicators and framework for assessing sustainable infrastructure

Much of the focus on sustainable infrastructure has concentrated on buildings and construction processes. To advance this thinking for other civil infrastructure systems (CIS), this paper outlines a framework that uses a set of proposed indicators to measure the sustainability of chosen infrastructure options and help select the preferred alternative in a multiobjective decision approach. Physically implementing "sustainable infrastructure" involves three life stages for any project: preproject planning, project implementation, and ongoing operations. It is critical to evaluate the sustainability of chosen options in each of these life stages. This research develops two categories of indicators, mandatory screening indicators (MSI) and judgment indicators (JI), and a multilayer approach for incorporating these indicators. A normalization procedure has been adapted to work within the framework to help compare alternatives across a range of indicators and different orders of data magnitude. A hypothetical example using a transmission line corridor is presented to illustrate how the framework can be applied.