Local Information

Prepare for weekend closures of northbound I-405 and SR 520 near Bellevue

Thursday, July 11, 2013 - 14:23

Kris Olsen, WSDOT communications, 206-440-4704 (Shoreline)
Puget Sound summer construction: www.wsdot.wa.gov/Construction/PugetSound

BELLEVUE – Drivers are urged to spend a few minutes planning their route now to avoid unexpected time waiting in traffic this weekend. Crews are closing both directions of State Route 520 across Lake Washington and northbound Interstate 405 through Bellevue July 13–14.

The Washington State Department of Transportation encourages drivers to take five minutes to map out a weekend strategy to deal with potentially long delays and heavy congestion due to the highway closures. A Mariners’ homestand at Safeco Field may also cause extra traffic congestion.

“We need drivers’ help to keep traffic moving,” said WSDOT Traffic Engineer Mark Bandy. “Whether you need to get to work, go shopping, run errands or go to an M’s game this weekend, planning ahead will be key. Drivers need to allow extra time, use alternate routes, take advantage of other forms of transportation and delay discretionary trips.”

Why are these closures necessary?
This weekend’s work is vitally important for the maintenance and preservation of critical commuter and freight corridors.

“There’s a lot of work to be done,” said WSDOT Northwest Regional Administrator Lorena Eng. “But combining it in one weekend helps reduce the number of closures we need this summer. We also want to avoid conflicts with special events like Seafair, the Bite of Seattle and the Bellevue Arts Festival.”

On northbound I-405, crews will replace all the concrete panels in the two left lanes between Southeast Eighth and Main streets. These panels – which stretch the length of a dozen football fields – are failing. Crews will also tear out and replace panels in many other locations. Panels in the two right lanes will be repaired later this summer.

On SR 520, bridge maintenance crews will inspect the floating bridge. This annual inspection includes checks of the electrical system and drawspan machinery. Crews will also tackle repair and maintenance tasks such as concrete and expansion joint repair. Eastside Transit and HOV project construction crews will take advantage of the closure to install an 11-foot-diameter, fish-friendly culvert beneath all lanes of SR 520 just west of I-405 and requires a multi-day closure to complete.

Additionally, much of this work can’t be performed in shorter, overnight closures. The concrete panels on I-405 need to cure for at least ten hours before vehicles can drive across them. The fish culvert requires digging a trench across all lanes of SR 520. The trench will be nearly 100 feet wide at road level and 34 feet deep.

Closure details


  • 10 p.m. Friday, July 12, to 5 a.m. Monday, July 15 : Northbound I-405 is closed from Southeast Eighth Street to SR 520, as well as the eastbound and westbound I-90 ramps to northbound I-405. Crews will begin reopening lanes at 4 a.m. Monday, July 15, with all lanes open by 5 a.m. The northbound I-405 exit to Southeast Eighth Street remains open through the weekend.

SR 520

  • 11 p.m. Friday, July 12, to 5 a.m. Monday, July 15: Both directions of SR 520 and all connected ramps are closed from Montlake Boulevard to I-405. Two sections of SR 520 remain open: I-5 to Montlake Boulevard and east of I-405.

“These closures will significantly affect traffic around the greater Seattle/Bellevue area,” said Bandy. “Drivers can expect congestion along both directions of I-5, I-405 and I-90.”

City streets in and around Bellevue will also experience extra congestion.

Alternate routes

  • I-5: No construction activity is planned for the Seattle area this weekend.
  • I-90: No construction activity is planned for the Seattle/Bellevue area this weekend.
  • To enter downtown Bellevue: Take Southeast Eighth Street to Street to 116th Avenue Northeast.
  • To leave downtown Bellevue: Use Northeast Eighth Street to get to northbound I-405. Use Northeast Tenth Street to reach eastbound SR 520.
  • Westbound SR 520 drivers can use southbound I-405 or 148th Avenue Northeast to go south.
  • I-90 drivers looking to head north toward Bellevue will be detoured to Bellevue Way or 148th Avenue Southeast.

Keeping traffic moving
WSDOT will help keep traffic moving during the weekend closures:

  • Alternate routes will be available to downtown Bellevue.
  • Additional Incident Response Teams will be on duty to quickly clear incidents and stalls.
  • The hours of operation for the I-5 and I-90 express lanes will be changed to accommodate traffic.
  • Traffic engineers will monitor travel conditions around-the-clock.

To reduce congestion, WSDOT is counting on drivers to:

  • Plan a travel strategy in advance. 
  • Reschedule or eliminate discretionary trips.
  • Travel early or late.
  • Allow at least one hour of extra time to reach your destination.
  • Know the detour routes before you go.
  • Carpool, ride a bicycle, or use public transportation options such as King County Metro or Sound Transit.

Tools for drivers

The work on I-405 is part of the $8.2 million I-405 Concrete Pavement Rehabilitation project. The SR 520 work is part of regular maintenance of the existing floating bridge and the $306 million SR 520 Eastside Transit and HOV project.

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