Project overview
In summer 2025, local developer Benaroya Company will start work to improve the SR 505 interchange over I-5 at Exit 63 in Lewis County. Tapani Inc. will build three roundabouts—at the on- and off-ramps and at Mickelson Parkway—between mileposts 2.24 and 3.08.
The project also includes a new westbound climbing lane between mileposts 2.53 and 2.88, widening the road for freight traffic, adding a shared-use path on the north side of the overpass, installing new signs and lighting, and repainting lane markings.
Note: This is a developer project--WSDOT will oversee the work to make sure it meets contract requirements for safety and design, and that traffic control follows the approved plan.
What to expect
During construction, contractor crews will reduce the travel speed and alternate travelers through a single lane closure with flaggers, to keep travelers moving through the work zone.
Temporary lane shifts may be used and a temporary detour route may be needed using Mickelson Parkway and North Military Road.
There are no closures scheduled along I-5 or at the on- and off-ramps.
Starting in late summer 2025, developer, Benaroya Company will construct three separate roundabouts along SR 505, over I-5 at Exit 63, between mileposts 2.42-3.08 in Lewis County. Roundabouts keep traffic flowing, improve safety and reduce collisions.
In 1997, Winlock adopted its first Growth Management Act (GMA) comprehensive plan, highlighting the I-5 and SR 505 interchange as a key area for future growth.
The plan focused on bringing in jobs, growing the city’s tax base, and encouraging development outside the downtown area. Over time, the plan was updated to reflect population growth and changing needs, with a focus on new commercial and industrial development west of I-5. With the updated plan, the Benaroya Company constructed a new commercial and industrial development area in southern Lewis County, along the west side of I-5, near Winlock.
To support both local and freight traffic connected to the nearby industrial and commercial area, Benaroya Company’s contractor, Tapani, will upgrade the I-5/SR 505 interchange. The work includes building roundabouts to keep traffic moving without long stops, widening the road for large trucks, adding a shared use path, upgraded lighting, and repainting lane lines to improve safety and visibility.
