Oregon’s Green Highway – Pioneering Low-Carbon Asphalt

Oregon’s I-205 widening project wasn’t just about adding lanes — it was a testbed for one of the state’s boldest environmental goals: cutting road construction carbon emissions by 40%. The Oregon Department of Transportation partnered with local suppliers to trial low-carbon asphalt mixes incorporating reclaimed asphalt pavement (RAP), reclaimed asphalt shingles (RAS), and bio-based binders.

The key breakthrough came from warm-mix asphalt production, which allowed mixing temperatures to drop by 50–100°F without compromising performance. This reduced fuel use and plant emissions significantly. Onsite asphalt recycling plants processed old pavement directly from the project, eliminating the need to haul material long distances.

In addition, noise-reducing open-graded friction courses were used in residential areas, cutting traffic noise complaints by 60%. Solar-powered lighting and electric vehicle (EV) charging points were also integrated along rest stops.

The I-205 expansion now serves as a model for sustainable highway building, with lifecycle studies projecting both environmental and cost savings for decades to come.