A new southbound Interstate 5 interchange featuring an exit ramp, overpass and roundabout opened on Jan. 24, 2026, at Exit 119/Steilacoom-DuPont Road, according to the Washington State Department of Transportation (WSDOT).
The work near Tacoma is part of the $240 million I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project. That project is widening the interstate and creating new HOV lanes designed to relieve chronic traffic congestion near Joint Base Lewis-McChord.
WSDOT awarded Guy F. Atkinson Construction a design-build contract in April 2023, with construction beginning a few months later
With the new southbound I-5 exit (119) to Steilacoom-DuPont Road open, those going to DuPont will turn right toward the new roundabout, while those heading to Joint Base Lewis-McChord will turn left and go over the overpass.
People on northbound I-5 going to DuPont or JBLM will continue to use the existing exit and the 1957 Steilacoom-DuPont overpass.
Travelers leaving DuPont for northbound I-5 will use the roundabout and new overpass.
People leaving DuPont Gate for northbound I-5 will yield to people traveling across the new overpass.
Coming this spring, the remainder of the new overpass will open to two-way traffic as a diverging diamond interchange.
Crews later will demolish the 1950s-era overpass, which is classified in poor condition. It does not meet current vertical clearance standards for I-5.
The demolition will allow crews to make changes to open the I-5 HOV lanes. The lanes are anticipated to open during late summer 2026. When complete, travelers will see HOV lanes between Mounts Road and Gravelly Lake Drive.
The entire I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project is expected to be completed by late 2026.
