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US20: Philomath Couplet

Main Street in Philomath, a small town southwest of Corvallis, is also a state highway, a freight route, and a vital connection to the Oregon Coast. Since the 1950s, efficient flow of traffic on this main commercial street has been a problem during peak seasons and a couplet solution was just a long-shot idea without funding. In the late 1990s, the idea started to receive funding for public outreach and conceptual design. Years later, Murraysmith was selected to complete these efforts and finally make this couplet a reality. Murraysmith engineers designed a hybrid couplet to expand the existing two-lane, two-way road: the eastern portion became a two-way, five-lane section, and the western portion was transformed into two westbound lanes on Main Street and two eastbound lanes on Applegate Street.


Not only did the new configuration address the decades-old traffic congestion problems, but the designs added bike lanes, sidewalks, hundreds of trees, and a new bridge to enhance fish passage at Newton Creek.

The multi-disciplinary team didn’t lose sight of Philomath’s rich history: a historic home was moved to a nearby location and endangered Nelson’s Checker-mallow plants were successfully relocated with participation from local high school students.

Main Street is no longer a bottleneck for commuters and travelers headed to the Oregon Coast. The hybrid couplet led to the revitalization of and plans for further development of the downtown area, adding even more character to this small town’s rich history.


Project Highlights

  • Hybrid couplet and five-lane two-way section
  • 5 miles of new and reconstructed roadway
  • Five-lane bridge across Newton Creek
  • New traffic signals and interconnects
  • Sidewalk and bike lane improvements
  • Stormwater management and water quality upgrades
  • 65 right-of-way files and acquisitions


  • 2007 ODOT Excellence in Project Delivery Award
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