The US26 Sunset Highway corridor connecting Multnomah County and Washington County, Portland and Hillsboro, will be the focus of an upcoming air quality study that is expected to test new and better methods to assess air quality impacts from transportation projects.

Regional and state air quality experts from the Oregon Department of Transportation (ODOT), the Oregon Department of Environmental Quality, Washington County, and Portland State University (PSU) are partnering with the City of Hillsboro to evaluate vehicular emissions with new measurements and models between the Vista Ridge Tunnel and Brookwood Parkway, in hopes that a better method will improve transportation-related air quality outcomes.

Dr. Linda George, a regionally and nationally recognized air quality scientist at Portland State University, will serve as the principal investigator for the air quality portion of the study. Dr. George and her team will lead the measurement of vehicular emissions in the US26 corridor. The team will also select up to three study sites along the corridor for more in-depth analysis for model development.

Nearly 150,000 vehicles commute along the Sunset Highway on an average work day. While arterials such as Tualatin Valley Highway and Cornelius Pass Road provide interregional connectivity for tens of thousands of vehicles per day, transit connections on the west side remain sparse. As commuters and freight operators continue to seek the most direct connection available, Sunset Highway likely will absorb additional vehicle traffic in the future.

The air quality study will be followed by a larger US26 transportation study that will evaluate ideas on how to address growing demand, along with opportunities that ODOT and its regional partners might take to improve on our multimodal system to support all communities. Both Washington County and the City of Hillsboro have contributed funding for the study to proceed.