Northbound Interstate 405 between Coal Creek Parkway Southeast and I-90 will shut overnight Wednesday into Thursday as WSDOT continues the Renton to Bellevue widening and express toll lane build.
According to the Washington State Department of Transportation project page for the I-405/Renton to Bellevue Widening and Express Toll Lanes Project, northbound I-405 closes from 11:30 p.m. Wednesday, August 12, to 4:30 a.m. Thursday, August 13, with a signed detour in place.
- Closure: All northbound I-405 lanes from Coal Creek Parkway SE to I-90.
- Window: 11:30 p.m. Wednesday, August 12, to 4:30 a.m. Thursday, August 13.
- Detour: Follow WSDOT signed detour signs during the overnight closure.
- Why: Active construction on the Renton to Bellevue widening and dual express toll lane system.
- Traveler decision: Avoid northbound I-405 on that overnight segment, or leave before 11:30 p.m. and recheck the live travel map.
If your late Seattle to Bellevue transfer still assumes an open northbound 405 corridor after 11:30 p.m. on August 12, rewrite the route before you leave the curb or the hotel garage.
WSDOT says travelers on I-405 between Bellevue and Renton should expect delays from lane reductions, nighttime closures, and ongoing construction, and should check the live travel map for alerts. Bellevue Reporter coverage of the broader August I-405 closure series matches the agency project timeline and underscores why Eastside drivers should treat each overnight window as a separate calendar check rather than one finished weekend event.
What closes on the night of August 12
The load-bearing fact for travelers is a full northbound mainline closure on a named segment for one overnight window.
Northbound I-405 from Coal Creek Parkway Southeast to I-90 is closed from 11:30 p.m. Wednesday to 4:30 a.m. Thursday. A signed detour is posted for that window.
That segment sits in the heart of Eastside airport and hotel traffic between Renton, Bellevue, and the I-90 interchange. Late arrivals into Sea-Tac who head north toward Bellevue hotels, and late departures from Bellevue back toward the airport corridor, are the first groups that feel it.
The closure is not a daytime full weekend shutdown. Daytime northbound traffic outside that overnight block still uses the corridor under ordinary work-zone conditions, subject to whatever lane reductions crews keep live.
How this fits the wider Renton to Bellevue construction week
WSDOT is building a two-lane express toll lane system between SR 167 in Renton and Northeast Sixth Street in Bellevue, generally adding one new lane in each direction and pairing it with the existing HOV lane to form dual express toll lanes.
The agency projects a 40-mile ETL system once the new lanes connect to the existing express toll lanes between Bellevue and Lynnwood and to the SR 167 HOT lanes through the I-405/SR 167 interchange connector. Forecasted opening to traffic is summer 2027, with construction funded in the $705 million contractor bid range.
That long program is why overnight mainline cuts keep appearing on the Eastside calendar. The August 12 northbound window follows other recent overnight and weekend work on the same corridor, including earlier southbound overnight work and prior weekend northbound full closures farther south toward Renton.
For a traveler, the program goal matters less than the next calendar block. The only decision that pays out tonight is whether your vehicle will need northbound I-405 between Coal Creek and I-90 after 11:30 p.m. on August 12.
Who should rebook the clock, not just the map
Airport transfers are the highest stakes use case. A late flight into Seattle that still needs a Bellevue hotel drop after midnight can land inside the closed northbound segment if the app keeps routing on I-405.
Deep Arrival’s Seattle cruise port to SEA airport transit guide remains the planning page for ship-to-airport and airport-to-downtown timing, while overnight Eastside freeway cuts force a separate check when the destination is Bellevue or points north of I-90 rather than downtown Seattle.
Hotel and rideshare drivers should treat the signed detour as mandatory inside the window, not optional. Work zones can include police, cones, and active equipment, and WSDOT reminds drivers to slow down, keep phones down, and expect delay even when they leave the closed mainline early.
Visitors building a Seattle day that ends with a late return to an Eastside hotel can keep daytime sightseeing on track. The Seattle things to do guide still covers the city-side itinerary; just do not assume I-405 northbound is a midnight recovery lane on August 12.
How to plan the overnight without guessing
First, confirm direction. The posted August 12 to 13 cut is northbound. Southbound is a different night and a different notice.
Second, confirm the clock. Leave the closed segment before 11:30 p.m. Wednesday, or wait until after 4:30 a.m. Thursday, unless WSDOT reopens earlier.
Third, confirm the detour in the field. The project page links a signed detour route for this overnight. Follow those signs rather than a map path that still draws the closed mainline in green.
Fourth, keep the live WSDOT travel map open if weather or crew progress changes the window. Night work is sensitive to conditions, and a reopened early hour only counts when the field signs or live map say so.
Commercial drivers and late freight moves on the Eastside should build the same buffer. A five-hour overnight closure is short on paper and long when the only remaining surface streets are carrying every displaced car and truck.
| If you… | Do this |
|---|---|
| Need northbound I-405 after 11:30 p.m. on August 12 | Leave earlier, or follow the WSDOT signed detour from Coal Creek Parkway SE toward the I-90 rejoin. |
| Land late at Sea-Tac bound for Bellevue | Tell the driver the northbound 405 segment is closed overnight and confirm an alternate before leaving the airport. |
| Travel southbound only that night | Recheck the live map for separate southbound work, but do not treat the northbound notice as a southbound ban. |
| Have a flexible Eastside hotel night | Return before 11:30 p.m. Wednesday or wait past 4:30 a.m. Thursday instead of fighting the detour. |
| Drive for work or freight after midnight | Build buffer and use the construction hotline or live map if the detour is congested. |
- Wednesday night: Treat 11:30 p.m. August 12 as the hard start for the northbound Coal Creek to I-90 closure.
- Thursday morning: Expect reopen around 4:30 a.m. unless WSDOT posts a change.
- Detour first: Follow signed detour markers, not a stale green I-405 line on the phone.
- Airport runs: Brief rideshare or hotel shuttles before the meter starts if Bellevue is the drop.
- Program context: Expect more overnight I-405 cuts through 2027 as dual express toll lanes take shape.
The material traveler change is a single overnight northbound mainline cut with a published clock and a signed detour.
If your next Eastside transfer falls after 11:30 p.m. on August 12, lock the alternate now instead of discovering cones at Coal Creek with a fixed hotel key or flight connection waiting.
When is northbound I-405 closed near Bellevue?
WSDOT closes northbound I-405 from Coal Creek Parkway Southeast to I-90 from 11:30 p.m. Wednesday, August 12, to 4:30 a.m. Thursday, August 13.
Is there a detour?
Yes. WSDOT says a signed detour route will be in place for the overnight northbound closure. Follow field signs over map defaults.
Why is the freeway closing overnight?
The work is part of the I-405/Renton to Bellevue Widening and Express Toll Lanes Project, which is building dual express toll lanes and related capacity on one of the state’s most congested Eastside corridors.
Does this close daytime I-405 on August 12?
The posted full northbound mainline cut is overnight. Daytime travel can still face lane reductions and work-zone delays, so check the live WSDOT travel map before you go.
