Towards precise sustainable road assessments and agreeable decisions

Abstract Highway engineers should ideally select sustainable road designs based on accurate and comprehensive assessments. Nevertheless, it is often challenging to identify the significant factors for quantifying the multidimensional concept of sustainability. Moreover, due to the multidisciplinary nature of sustainability, the outputs from various assessments are often diverse, and, hence, their significance must be suitably examined during the decision-making process. In the present study, economic, environmental, and social life cycle assessments (LCAs) were considered in an integrated manner, and 12 measurable indicators were thereby recommended for assessing specific road designs. Since the LCA outputs are usually sensitive to the quality of the inputs used for the calculation, customizable LCA models and project-specific data are required to produce a more precise estimate than that based on the standard available information. In this study, a hybrid analytic hierarchical multi-criteria group decision-making model was employed to select the sustainable design. In addition, the application of the proposed approach was demonstrated by selecting a sustainable road design for El Paso, Texas. The environmental outputs were normalized using a relatable reference system to facilitate understanding. The assessments were then reviewed by eight experts, and a group-agreeable design was selected.