Oregon DOT: Applying a novel GHG Lens to influence DOT Investments 

Abstract
ODOT has developed and continues to refine a novel GHG Index metric and process to inform several key decisions in our State Transportation Investment Program (STIP). This simple approach has potential application in other states. Nationally, the transportation sector is the largest contributor to human-influenced climate change representing 40% of total Greenhouse Gas (GHG) emissions are a, with sector in Oregon. The bulk of those emissions are from on-road travel, leading to public examination of supportive roadway investments.

In 2020, the Oregon DOT with the governor’s support (EO20-04) committed to assess the impact of the state’s transportation system investments on climate by adding a GHG lens to the 3-year STIP, a complicated and core agency funding program. Background research indicated that providing climate information earlier in the process, where it could affect overall programmatic funding as well as project prioritization within programs, would have the biggest return. That required a metric that used limited project details calculated for hundreds of projects of diverse types under quick turnarounds, barring the use of traditional detailed project GHG methods. Instead, ODOT developed a new GHG Index based on data available in early project stages.

ODOT identified three major decision points during STIP development (Figure 1). Phase 1 and 2 employ the new qualitative GHG Index, while Phase 3 uses traditional more detailed full GHG quantification analysis on the final set of STIP projects.

The GHG Index maps dollars spent on certain attributes within a project towards meeting GHG outcomes. For example dollars spent expanding roadway lanes would score negatively for GHG mitigation, but be offset by positive costs spent on the adjacent bike lane, while pavement costs would be neutral. Each project ends up with a comparative score that can also be aggregated to programs. Recognizing the tradeoffs of climate with other goals, indices for other DOT objectives were also developed in Phase 1including equity, safety, and state of good repair. Project funds are allowed to score positively towards multiple goals.

While simple and qualitative, both Phase 1 and 2 analyses are designed to successfully enable transparent trade-off conversations, constructive and robust public input earlier in the STIP development process, in advance of major decision-points. The ability to see the impact of funding level adjustments across Department priorities highlights which funding scenarios and portfolio of projects are projected to yield the best GHG emissions reduction outcomes and what additional modifications to funding levels would further advance beneficial climate outcomes. Since project costs are a constant throughout the project lifecycle, projects and programs can be monitored as projects change over time. Capturing decisions in the STIP allows project decisions to be made earlier in the process, heading off questions that re-occur during the project planning phase. The STIP process is being refined with future expansion planned to cover climate adaptation and other agency goals in all phases.