New I-5 overpass near JBLM opening this weekend. 1950s overpass demo next month
On Sunday morning, drivers from DuPont and Joint Base Lewis-McChord will see a new on-ramp to southbound Interstate 5 via the new Steilacoom-DuPont Road diverging diamond interchange.
When the new on-ramp opens at 7:30 a.m. on March 22, the old 1950s-era overpass will be closed to all traffic, according to the Washington State Department of Transportation. It’ll be demolished on April 3 and April 4.
30-min delays during overpass demolition
During the night April 3-4, drivers will follow detours in both directions of I-5 through Exit 119 at Steilacoom-DuPont Road, according to WSDOT.
Plan to spend at least 30 extra minutes of driving and expect stop-and-go traffic approaching the work zone, WSDOT said in a press release. Lane closures will happen from 10 p.m. each night until 6 a.m. the following day.
The overpass demolition will allow crews to continue building HOV lanes in both directions of I-5, WSDOT said.
Those HOV lanes will open late summer 2026 as part of the $240 million I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project.
