Drivers in DuPont and commuters heading to Joint Base Lewis‑McChord are about to get a whole new routine. A reworked southbound I-5 Exit 119 with an overpass, ramp and roundabout is set to open Saturday, and crews are closing lanes overnight this week to stitch the new pieces into place. It is the latest phase of a multi-year push to ease chronic congestion near the base and add safer walking and biking access between DuPont and JBLM.
What’s Opening At Exit 119
The new southbound Exit 119 will route traffic into a roundabout and a separate overpass: drivers bound for DuPont will peel right into the roundabout, while those heading to JBLM will turn left and cross a new bridge over I-5. Planners also built in a barrier-separated shared-use path so people can walk, bike or roll between DuPont and the base, according to the Washington State Department of Transportation.
Nighttime Closures And Detours
To get the new configuration ready for prime time, crews are rolling out detours and overnight closures this week as they complete the final connections. As reported by The News Tribune, Steilacoom‑DuPont Road approaching the new roundabout will close nightly from 9 p.m. to 5 a.m., the northbound I-5 off- and on-ramps at Exit 119 will shut during evening hours, and single-lane closures on I-5 are scheduled overnight with signed detours in place for drivers.
How Traffic Will Flow
Once the southbound ramp reopens early Saturday, motorists taking the new exit will either head into the roundabout toward DuPont or cross the new overpass toward the JBLM DuPont Gate. Northbound drivers going to DuPont or the base will keep using the existing 1957 bridge for now. These changes are part of the I-5 Mounts Road to Steilacoom‑DuPont Road corridor project and are designed to keep three through lanes open on I-5 while construction continues, according to the Washington State Department of Transportation.
Timeline: DDI, Demolition And HOV Lanes
The News Tribune reports that the work is part of a roughly $240 million corridor project to widen I-5, and that WSDOT expects the new HOV lanes to open in late summer 2026. The agency anticipates the overall project will wrap up by late 2026. As The News Tribune explains, crews will not remove the old bridge until the new route is fully in service.
Tips For Commuters And JBLM Personnel
Drivers should plan for delays around the interchange during the evening and overnight work and follow posted detours and flaggers. Base commuters may want to budget extra travel time for the first few days while everyone learns the new pattern. A schedule roundup from Yahoo News echoes WSDOT's reminder to slow down in work zones and to sign up for project updates.
Once the dust settles, the new interchange and overpass are expected to smooth traffic for both civilian and military travelers heading into JBLM, while finally providing a dedicated walking and biking link over I-5. Anyone planning to use Exit 119 this week should check local traffic alerts before heading out.
