Tigard and Tualatin commuters who use Interstate 5 through central Portland will need a new plan starting Friday, Sept. 11.
All southbound I-5 lanes will shut down for through traffic between Interstate 405 and Interstate 84 in the Rose Quarter for up to five weeks, running 24 hours a day, seven days a week.
The closure affects roughly 120,000 vehicles daily, including about 11,700 trucks carrying more than $100 million in goods, according to ODOT's Aug. 11 press release. Commute times through the area could double or triple. One lane of I-5 southbound will remain open from I-405 to the Broadway/Weidler exit near the Moda Center for local access only.
"We evaluated several options on how to do this vital portion of the project, and the full closure is the quickest and most efficient way to do it," ODOT project delivery manager David Kim said in the release. "Crews will work 24/7 and reopen the interstate as soon as the work is completed."
Why it's happening
The concrete on the elevated highway structure south of the Moda Center hasn't been replaced since 1985. The 1.8-mile stretch is the only two-lane section of I-5 in a major urban area between Canada and Mexico, carries the highest crash rate on any urban interstate in Oregon and is the state's No. 1 traffic bottleneck, according to ODOT's project page.
Crews will remove the surface layer, make structural repairs, replace bridge joints, repave and continue seismic improvements underway since fall 2025. The work is Phase 1A of the larger I-5 Rose Quarter Improvement Project, which carries a total estimated cost of $1.96 billion to $2.08 billion. Phase 1A alone costs $75 million.
What Tigard and Tualatin drivers should know
ODOT's official detour sends all southbound I-5 traffic onto I-405 southbound. Regional commuters, including those heading between Portland and Tigard or Tualatin, are directed to Interstate 205 to bypass central Portland entirely.
Locally relevant surface routes include OR 217 north to US 26 into Portland and OR 99W north through Tigard, though ODOT has not designated those as official detours for this closure. Even drivers who don't normally use I-5 should expect delays as traffic spills onto alternate routes across the region.
I-5 northbound remains open.
Transit options
TriMet's WES Commuter Rail connects Tualatin and Tigard Transit Center to Beaverton Transit Center on weekdays, where riders can transfer to MAX. Morning departures from Tualatin run at 5:26, 6:11, 6:56, 7:41 and 8:26 a.m., according to the current WES schedule. Riders should check trimet.org for any schedule changes during the closure.
The MAX Yellow Line runs approximately every 15 minutes and serves downtown Portland. Commuters can park at TriMet's Delta Park/Vanport or Expo Center park-and-ride lots and continue by train.
TriMet's trip planner at trimet.org compares routes across TriMet and C-TRAN services. Riders can pay with a contactless bank card, Hop card or smartphone.
What's next
The closure is expected to last through mid-October. Drivers can monitor conditions at TripCheck.com and sign up for travel alerts at i5rosequarter.org/contact. Portland Public Schools' first day for most students is Wednesday, Aug. 26, just over two weeks before the shutdown begins, meaning school-year traffic will already be in full swing when lanes close.
