Overnight Friday, April 4 and Saturday, April 5, and again Friday, April 11 and Saturday, April 12, crews will reduce travel lanes in both directions of I-5 to a single lane to set bridge girders over the freeway. That one lane will detour up and over the Steilacoom-DuPont Road off- and on-ramps. See closure details in "what to expect" section below.
Project overview
This project is intended to help relieve chronic traffic congestion and improve mobility along I-5 near Joint Base Lewis-McChord. Crews will rebuild the Steilacoom-DuPont Road (Exit 119) interchange and extend I-5 HOV lanes to Mounts Road.
What to expect
I-5 closure to set new overpass girders
Nighttime travelers who use I-5, or the Steilacoom-DuPont Road overpass in DuPont, will see some delays and detours in April. Over two weekends, construction crews will place 13 girders over I-5, just north of the existing Steilacoom-DuPont Road overpass.
Overnight Friday, April 4 and Saturday, April 5, and again Friday, April 11 and Saturday, April 12, crews will reduce travel lanes in both directions of I-5 to a single lane. That one lane will detour up and over the Steilacoom-DuPont Road off- and on-ramps. Law enforcement will be in place to assist with traffic control at both the northbound and southbound I-5 ramps.
- I-5 lane closures start at 8 p.m.
- At 10 p.m. one lane will begin using the off- and on-ramps at Steilacoom-DuPont Road.
- Lanes begin reopening at 6 a.m. Saturday, April 5 and Sunday, April 6.
- The same closure hours will be in place overnight Friday, April 11 and Saturday, April 12.
Overnight closure of Steilacoom-DuPont Road overpass
To keep travelers moving on I-5, the Steilacoom-DuPont Road overpass will close during overnight while girders are installed. Here’s what to expect:
- Northbound I-5 travelers needing to use exit 119 at Steilacoom-DuPont Road will detour to 41st Division Drive and return to southbound I-5 to exit 119.
- Travelers on Steilacoom-DuPont Road heading to northbound I-5 will detour to southbound I-5 to exit 118 at Center Drive and return to northbound I-5.
- Emergency vehicles will have access to the Steilacoom-DuPont Road overpass.
Why we’re closing I-5
The weekend overnight closures allow crews from Atkinson Construction to set 170-foot-long girders, each weighing approximately 206,000 pounds. The girders will support a replacement overpass and diverging diamond interchange. The new overpass will be completed in 2026 as part of the I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project.
Backups are expected and travelers on both directions of I-5 should plan for additional overnight travel time.
The project will add HOV lanes to both directions of I-5.
Crews will rebuild the Steilacoom-DuPont Road interchange.The new interchange will connect to Steilacoom-DuPont Road near Pendleton Avenue. Workers will replace the existing at-grade railroad crossing. Crews will build a new bridge. It will carry travelers over the tracks.
