New I-5 overpass, interchange to JBLM set to open. Detour details in meantime
AI-generated summary reviewed by our newsroom.
- WSDOT opens new southbound I-5 exit 119, adding overpass and roundabout.
- Traffic shifts open Jan 24; motorists use new ramp to reach JBLM and DuPont.
- Project will remove 1950s overpass, expand I-5 and add HOV lanes by late 2026.
Pending good weather, a new southbound Interstate 5 interchange with an exit ramp, overpass and roundabout will open at Exit 119/Steilacoom-DuPont Road on Saturday, according to the Washington State Department of Transportation.
As previously reported by The News Tribune, the work is part of the $240 million I-5 Mounts Road to Steilacoom-DuPont Road Corridor Improvements project, which seeks to widen I-5 and create new HOV lanes to relieve chronic traffic congestion near Joint Base Lewis-McChord.
Prior to Saturday, the following closures and detours will be in place, according to WSDOT:
Steilacoom-DuPont nightly closure information
- Jan. 21-23, Wednesday to Friday
- 9 p.m. to 5 a.m. - Both directions of Steilacoom-DuPont Road approaching the roundabout will close. Signed detours will be provided.
I-5 nightly closure information
Wednesday, Jan. 21
- 7 p.m. to 4:30 a.m. – Northbound I-5 off- and on-ramps at Steilacoom-DuPont Road will close.
- 7:30 p.m. to 4:30 a.m. – A single lane of northbound I-5 will close.
- 8 p.m. to 4:30 a.m. – A single lane of southbound I-5 will close.
Thursday, Jan. 22
- 7 p.m. to 4:30 a.m. – Northbound I-5 off- and on-ramps at Steilacoom-DuPont Road (Exit 119) will close.
- 7:30 p.m. to 4:30 a.m. – A single lane of northbound I-5 will close.
- 8 p.m. to 4:30 a.m. – Southbound I-5 exit to Steilacoom-DuPont Road (Exit 119) will close.
- 8 p.m. to 4:30 a.m. – A single lane of southbound I-5 will close.
Friday, Jan. 23
- 8 p.m. to 6 a.m. – Northbound I-5 off- and on-ramps at Steilacoom-DuPont Road (Exit 119) will close.
- 8 p.m. to 8 a.m. – A single lane of northbound I-5 will close.
- 9 p.m. to 6:30 a.m. – Southbound I-5 off-ramp to Steilacoom-DuPont Road (Exit 119) will close.
- 9:30 p.m. to 8 a.m. – Up to two lanes of southbound I-5 will close.
During the early morning hours of Saturday, Jan. 24
- Southbound I-5 Exit 119 to Steilacoom-DuPont Road will reopen.
- Travelers will begin using the new southbound I-5 Exit 119 to Steilacoom-DuPont Road to reach JBLM or northbound I-5.
- Those going to DuPont will turn right toward the new roundabout.
- People 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.
In the spring, the remainder of the new overpass will open as a diverging diamond interchange for two-way traffic, according to WSDOT. Once open, people will be able to walk, bike or roll between DuPont and JBLM.
“Crews later will demolish the 1950’s era overpass, which is classified in poor condition. It does not meet current vertical clearance standards for I-5,” according to WSDOT. “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.”
