We have completed the Interchange Area Management Plan (IAMP) that documents the traffic volumes and interchange performance in order to define a level of service and to ensure that level will extend into the future. The IAMP establishes an agreement with local government and stakeholders on the transportation solutions, policies, and actions needed to improve the interchange.
The IAMP and the appendix files are available in the document library at the bottom of this page.
Design of the Interchange
We considered many factors such as safety, traffic flow, short and long-term transportation needs as we designed the new interchange. During the development process, the design was narrowed to a concept that minimizes the footprint of a full interchange. However, some private property will need to be acquired to construct the project.
The preferred design is called a Diverging Diamond. The concept image represents how ramps and roads connect to I-5. The design realigns some of county roads and private-property accesses. Considerations included survey, environmental and traffic data, and conversations with property and business owners. These are all documented in the IAMP.
Reconstructing this interchange is a high priority of the Mid-Willamette Valley Area Transportation Commission, Marion County and ODOT.
Approximately 32,000 vehicles use Exit 278 Aurora-Donald or travel past the ramps entering and exiting I-5. The volume of traffic, proximity of roads and access points, and visibility issues cause congestion and safety concerns around the interchange. Built about 60 years ago for a much lower traffic volume, the interchange has been over capacity at peak times for many years.
It has significant safety issues and does not operate like a busy interchange should. Phase 1 construction will make improvements to the interchange and address some of the current issues.
September 30, 2020: Marion County Board of Commissioners public hearing to adopt the IAMP.
- 9:30 a.m. The Board of Commissioners session agenda will be posted about two weeks before the meeting on the Marion County website. Please note, this meeting is being held by Marion County.
November 12, 2019:
November 13, 2019:
North Marion High School Commons, 20167 Grim Road NE, Aurora, OR 97002
4:00-5:30 p.m. Business and Stakeholder Engagement Group meeting.
6:00-8:00 p.m. Public Open House. Viewed recommended future full interchange design with refined road connections, as well as the recommendations for Phase 1 improvements.
Phase 1 Design 2020
Construction in 2022 (Bid Let 2021)
Aurora-Donald Interchange (Exit 278)
Cost and Funding
The project was originally funded at $3.4 million. The Keep Oregon Moving transportation funding package, HB 2017, allocated nearly $25 million more for a total of $28.3 million to complete planning for the full interchange and design, and for construction of Phase 1.
$18 million will be used to construct Phase 1 improvements. Funding is not available for construction of a full interchange.