The Marion County Board of Commissioners last week gave their approval to the first phase of a massive overhaul of the Donald-Aurora interchange on Interstate 5.
Although the plan to break the nearly $80 million project into two parts because of a lack of funding was not well received by commissioners, they pointed out the pressing need for safety improvements at one of the area’s most dangerous intersections and concluded that even the first phase would be better than nothing.
The county’s approval means the plan will now go before the Oregon Transportation Commission, likely in December. If it is given the green light, opening bids for phase 1 would be expected in November 2021, with construction slated for 2022 and 2023.
The preferred concept is a “diverging diamond interchange,” a design pioneered in France that would require overpass traffic to briefly switch over to the wrong side of the road. Such interchanges are designed to improve safety by eliminating the need for left turns.
In executing the concept at the Aurora-Donald interchange, the Oregon Department of Transportation plans to construct a new I-5 bridge; realign the current travel lanes on I-5; lengthen and widen the north and southbound entrance and exit ramps; and realign Ehlen and Bents roads and Dolores Way.
The existing interchange was built 60 years ago and designed to handle the traffic of that day, when its closest neighbors were a handful of quiet farms. Today, it is the access point for three busy truck stops, as well as an RV park, and sees approximately 32,000 vehicles per day.
ODOT officials admit the interchange has been over capacity at peak times for many years. The transportation agency has acknowledged “it has significant safety issues and does not operate like a busy interchange should.”
The first phase will come at an estimated cost of $50 million and is fully funded, with the lion’s share coming from House Bill 2017, the so-called “Keep Oregon Moving” package.
Phase 2 has a $29 million price tag and is still in search of funding sources. An ODOT senior planner told commissioners last week that if the project had been done in one shot instead of two parts, it could have been realized for “only” $71 million — a savings of $8 million.