Girder setting for new I-5 overpass brings nighttime lane and ramp closures Sept. 15-20 in DuPont

DUPONT – Another round of girder setting for a new overpass in DuPont is scheduled for mid-September. Last April, crews installed girders for a new diverging diamond overpass over Interstate 5. On Monday, Sept. 15 they will return to the area – this time setting girders over the railroad next to the highway. Nighttime travelers who use I-5 through DuPont and Pendleton Avenue on Joint Base Lewis-McChord should plan for delays and detours.

Construction crews working for the Washington State Department of Transportation will place 17 additional girders. The girders measure up to 156 feet long and weigh up to 171,000 pounds. They will connect to the new overpass built in April.

The new diverging diamond overpass will connect to the new roundabout in DuPont.

I-5 lane and ramp closures

Monday, Sept. 15 to Wednesday, Sept. 17:

• A single lane of southbound I-5 will close from 8 p.m. to 4:30 a.m. nightly.
• The Center Drive off-ramp to southbound I-5 will be closed from 8 p.m. to 4:30 a.m. nightly.
• The Steilacoom-DuPont Road on-ramp to southbound I-5 will be closed from 8 p.m. to 4:30 a.m. nightly. 

Thursday, Sept. 18: 

• The southbound I-5 off-ramp to Steilacoom-DuPont Road will be closed from 8 p.m. to 4:30 a.m.
• Southbound I-5 will be reduced to a single lane beginning at 8 p.m. All lanes will reopen at 4:30 a.m. the following morning. 

Friday, Sept. 19 and Saturday, Sept. 20:

• Southbound I-5 will be reduced to a single lane beginning at 9:30 p.m. All lanes will reopen at 6 a.m. each following morning.
• Southbound I-5 off-ramp to Steilacoom-DuPont Road will be closed from 9 p.m. to 6:30 a.m.

Traffic holds in DuPont Sept. 15-17

Between 9 p.m. and 5 a.m. nightly, crews will intermittently stop traffic for up to 10 minutes at the following DuPont intersections:

• Center Drive and Wilmington Drive.
• The new Steilacoom-DuPont Drive roundabout.

The traffic holds allow crews to safely transport the massive concrete girders. 

Southbound I-5 in DuPont will be reduced to a single lane nightly beginning at 8 p.m. All lanes will reopen at 4:30 a.m. daily. 

Pendleton Avenue closed Sept. 8 and 9

In addition, crews will install three girders on the I-5 overpass at Pendleton Avenue. Rebuilding the overpass gives additional clearance to vehicles on Pendleton Avenue.

• Pendleton Avenue will be closed from 8 p.m. to 4 a.m. nightly.
• Southbound I-5 will be reduced to a single lane 10:30 p.m. to 4 a.m. nightly.
• 41st Division Drive on-ramp to southbound I-5 will close from 8 p.m. to 4:30 a.m. nightly.

Project information 

The new overpass will be completed and opened to eastbound traffic in early 2026. It will fully open to traffic in spring 2026 as part of the I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project. 

Please help keep road workers safe. When approaching a work zone, please remember to: 

• Slow down – drive the posted speeds for worker and traveler safety.
• Be kind –workers are out there helping to keep people safe and improve the roadways.
• Pay attention – both to workers directing travelers and surrounding traffic.
• Stay calm – expect delays, leave early or take alternate routes if possible; no meeting or appointment is worth risking someone’s life.