Construction equipment in the area will cause crews to close the trail between Pine Street and the State Street roundabout the week of Feb. 10.
The roads have since reopened in the area of the incident.
The speed limit decrease will take effect on the 2.5 mile stretch of I-5 after the crews finish installing new signs on Wednesday.
At this time, there is no estimate of when both lanes will reopen.
Crews are working to finish installing lights at the intersection following the roundabout’s completion in August.
The county council will hold a public hearing on the change on Jan. 14, 2025.
The project will bring a new sidewalk, traffic signal and more to the Fairhaven area.
WSDOT has not disclosed a reason for the closures, but they are encouraging drivers to use the Bow Hill rest areas instead.
The change comes after a fatal crash at the intersection on Oct. 31, when an 11-year-old child was killed by a speeding driver who was going around 100 mph.
The man faces several charges, including assault, reckless driving and driving without a valid license.