Get ahead of the curve: how to navigate weekend closures on I-405 this summer and keep your travel on track!

By Julie Moon

Summer is just around the corner and we know how important it is for you to make the most of the sunshine while it lasts. The upcoming construction seasons in the Puget Sound region will see several projects that will have lane closures to safely complete work, including several weekend closures on Interstate 405 coming up in the next few months. We will have lane reductions on two consecutive weekends in June and also full I-405 closures on one weekend in August and one weekend in September.

The construction is part of the I-405, Renton to Bellevue Widening and Express Toll Lanes Project. The project also builds infrastructure for Sound Transit’s Stride bus rapid transit system including a new inline transit station at Northeast 44th Street in Renton. Bus rapid transit, paired with the ETL system, will provide more reliable transportation options for people – no matter how they get around.

Partial weekend closures in June

For two weekends in June, at least two lanes – sometimes more, depending on the time of day and location – of northbound I-405 will be closed to repave the road and install new drainage systems. The closures will start on Friday nights and end on Monday mornings.

Anticipated June closure dates:

• 10 p.m. Friday , June 2 to 5 a.m. Monday, June 5: Two lanes of northbound I-405 will be closed between Coal Creek Parkway and Northeast Sixth Street.
• 10 p.m. Friday, June 9 to 5 a.m. Monday, June 12: Two lanes of northbound I-405 will be closed between Coal Creek Parkway and Northeast Sixth Street.

There will not be any detour routes, so it's important to plan your travel accordingly and expect delays during these weekend lane reductions. At least one lane will remain open for drivers, though speeds may be slower.

Full weekend closures in August and September

For one weekend in August and one in September, northbound and southbound I-405 will be fully closed. The closures will start on Friday nights and end on Monday mornings. Closing the road allows our crews to do this work safely and efficiently. Detour routes will be available to assist you in avoiding the closures and arriving at your destination safely.

Anticipated August closure dates:

• 10 p.m. Friday, Aug. 18 to 5 a.m. Monday, Aug. 21: All northbound and southbound lanes on I-405 will be closed between Sunset Boulevard Northeast and Coal Creek Parkway.
• Several ramps will also be closed:
  - Sunset Boulevard Northeast on-ramp to northbound I-405
  - All ramps at North 30th Street to I-405
  - All ramps at Northeast 44th Street to I-405
  - All ramps at 112th Avenue Southeast/Lake Washington Boulevard Southeast (Exit 9) to I-405
  - Coal Creek Parkway Southeast on-ramp to southbound I-405

During the August closure, crews will be replacing a fish barrier with a box culvert, which is a structure that helps fish safely swim under the highway. This will improve the fish habitat upstream and make it easier for fish to move around.

Anticipated September closure dates:

• 10 p.m. Friday, Sept. 8, to 5 a.m. Monday, Sept. 11: All lanes of northbound and southbound I-405 will be closed between Coal Creek Parkway and Sunset Boulevard Northeast.
• Several ramps will also be closed:
  - Sunset Boulevard Northeast on-ramp to northbound I-405
  - All ramps at North 30th Street to I-405
  - All ramps at Northeast 44th Street to I-405
  - Northeast 44th Street over I-405
  - All ramps at 112th Avenue Southeast/Lake Washington Boulevard Southeast (Exit 9) to I-405
  - Coal Creek Parkway Southeast on-ramp to southbound I-405

As part of the project, crews will reconfigure the Northeast 44th Street interchange in Renton to include a new, inline Bus Rapid Transit station and direct access ramps to and from the future express toll lanes, with Northeast 44th Street passing beneath the highway. As part of this work, crews have been building a new northbound I-405 bridge near Northeast 44th Street. During the September closure, crews will shift all lanes of I-405 traffic to the new bridge to begin construction of the new southbound alignment.

Detour routes for full closures in August and September

Whether driving on northbound or southbound I-405, you will need to take a different route during these closures.

Northbound drivers will exit at State Route 900/Sunset Boulevard Northeast in Renton and rejoin I-405 at Coal Creek Parkway in Bellevue. Another option is to follow additional detour signs to rejoin northbound I-405 at Southeast Eighth Street near downtown Bellevue.

Southbound drivers will exit at Coal Creek Parkway and get back on I-405 at North Southport Drive in Renton. They can also exit at Southeast Eighth Street or Lake Washington Boulevard Southeast (Exit 9) and follow additional signs to detour to North Southport Drive.

What can I expect?

• Delays and congestion: Plan for slower travel times on I-405 and longer waits along the detour routes.
• Reduced speed limits in work zones: Anytime you're in or approaching these construction work zones, please give our crews room, slow down, be patient, and stay alert.
• Potential noise: Construction work can also make loud noises and cause vibrations.

Stay safe and informed

• Stay updated with the latest traffic and closure information using our real-time travel map or downloading our app.
• Stay informed on I-405 construction by subscribing to the Eastside of Lake Washington Transportation News listserv.
• If you have questions about this closure or the Renton to Bellevue Project, contact our project office at i405sr167program@wsdot.wa.gov, check out our Renton to Bellevue Project webpage, or call the 24/7 construction hotline at 425-818-0161.

We recognize extended closures can be inconvenient, so we encourage you to use other routes, postpone discretionary trips if possible, ride transit, carpool or use other alternative modes of transportation and/or travel at off-peak times. Make sure to “know before you go” and plan ahead to make the most out of your travel times this summer!