The New Roundabout in West Linn is Expected to Reduce Crashes by 48% Per Year

The new roundabout connecting OR 43 to northbound I-205 in West Linn opened this month. 

The new roundabout connecting OR 43 to northbound I-205 in West Linn opened this month in a significant step forward for the region's transportation infrastructure. This is the first roundabout constructed on a state highway, OR 43, in the Portland area, and it’s also the first roundabout connected to an interstate on-ramp in Oregon.

The roundabout represents a significant safety improvement compared to the previous road configuration, with two separate on-ramps connecting OR 43 to northbound I-205. During the I-205 Abernethy Bridge Project’s design phase, an Intersection Control Study was completed that showed a roundabout would dramatically improve safety and smooth traffic flowing onto northbound I-205 from OR 43. The reason is the previous road arrangement had two points of entry from OR 43 onto northbound I-205, which resulted in too many vehicles merging within a confined space. By contrast, the single point of access to northbound I-205 from OR 43, made possible by the new roundabout and upgraded on-ramp, allows for a smoother and safer influx of vehicles onto northbound I-205. 

The roundabout will virtually eliminate head-on crashes and is expected to reduce the overall number of crashes in the area by 48%. To learn more about how roundabouts enhance safety, please listen to this Freakonomics podcast episode. Another benefit is smoother traffic flow, resulting in reduced fuel consumption and emissions.  

If you need a refresher on navigating a roundabout, ODOT has helpful resources, including videos, informative animations for reference and factsheets.  

Drone footage of construction and preparation for the new OR 43 roundabout in West Linn.

The Abernethy Bridge Construction Project thanks the public for their patience during the closures and detours required to support this construction. We also appreciate everyone’s continued support as the project progresses toward its 2025 completion.

For real-time updates and alerts, please sign up for text and email alerts to receive timely information to help plan your travel schedules effectively. For more updates on the I-205 Abernethy Bridge project, follow ODOT's Facebook, Instagram, and Twitter.