Challenges in Developing a Transportation Sustainability Rating System That Meets the Preferences of a Department of Transportation

Abstract

Increasingly, sustainability is a key indicator for planning transportation projects. As a result, evaluating the applicability of various transportation sustainability rating systems (TSRS) for adoption is important for the transportation industry in general, and for specific transportation organizations in particular. Several contending TSRSs are emerging, and provide various methods of guidance with regard to sustainability for infrastructure projects throughout project delivery. Different TSRSs, for example, employ different methods to determine or quantify sustainability and emphasize different sustainability factors. As a result, comparing the various systems and their suitability for implementation by a specific transportation organization can be a challenge. In this research, the authors apply the Analytical Hierarchy Process (AHP) as the method to assist in such an evaluation according to the Colorado Department of Transportation’s (CDOT’s) preferences. Application of AHP in previous research resulted in identification of the Infrastructure Voluntary Evaluation Sustainability Tool (INVEST) as the most suitable TSRS for CDOT. Here we compare previous results to CDOT’s recently developed custom TSRS. Findings indicate that CDOT’s own custom system ranks fourth compared to existing and publicly available TSRSs according to its own stated preferences. This unexpected result highlights unique issues and challenges related to developing an effective TSRS for a Department of Transportation (DOT), as well as potential issues and biases when applying AHP to assess sustainability tools.