The portion of Highway 530 near Oso that was damaged in the March 22 mudslide reopened to two-way traffic this evening, according to the Washington State Department of Transportation (WSDOT).
The speed limit will remain at 25 mph, WSDOT said. Stopping or pulling over along the stretch of highway is not allowed, and periodically during construction, drivers can expect to see flaggers on the temporary roadway. There are no restrictions for height or size of vehicles, but oversized loads will need a permit.
“This temporary roadway will help to strengthen connections between Arlington, Oso and Darrington, as well as the rest of our state, just in time for summer visits to local events,” WSDOT Regional Administrator Lorena Eng said in a news release.
The roadway will have to be rebuilt and elevated, WSDOT said, because the mudslide changed the geography of the valley floor and the North Fork of the Stillaguamish River, increasing the chance of flooding. The $28.1 million construction project for the new roadway is expected to begin in early July, starting on the east side of the slide area and moving west. It’s expected to be completed in early October.
During construction, traffic will have to return to the Seattle City Light access road on several occasions, which will be scheduled on weekdays as often as possible, WSDOT said.
The north Snohomish County highway was damaged and both directions were blocked after the massive mudslide on March 22. Traffic has operated on a one-way basis with a pilot car since late May.