Update: Weekend Traffic Alert - Northbound I-405, 520 Bridge Closures

Both directions of State Route 520 across Lake Washington and northbound Interstate 405 through Bellevue will close simultaneously during the weekend of July 13-14 for critical inspections, repairs and construction. 

The Washington State Department of Transportation urges drivers to “take five” – take five minutes to check WSDOT’s online travel resourcesand plan weekend routes, or consider Interstate 5 for an alternate north-south route.

“The weekend closure of SR 520 and northbound I-405 will significantly affect traffic across the Puget Sound region,” said WSDOT’s Northwest Regional Administrator Lorena Eng. “We realize that not everyone can completely change their commute. But for those who have a choice, options such as vanpooling, carpooling or other forms of transportation can help avoid heavy congestion.”

Drivers should plan for long delays on I-90 near the detour routes, westbound SR 520 approaching I-405, northbound I-405 where all traffic will exit to SE Eighth Street, and I-5 through downtown Seattle. Surface streets in and around Bellevue will experience extra congestion as well.

Friday, July 12, northbound I-405 will close at 10 p.m., and both directions of SR 520 will close at 11 p.m. All lanes of both highways will reopen by 5 a.m. Monday, July 15.

Why shut down both highways at once?
This work is critically important for maintenance and preservation of vital commuter and freight corridors. By simultaneously closing both SR 520 and northbound I-405, crews will complete this time-consuming work in a short period, reducing the need for nightly closures over a much longer stretch. In addition, there are a limited number of weekends available this summer to complete necessary work on numerous road construction and maintenance projects.

“Combining closures helps us limit summer weekend impacts on drivers while still allowing us to complete major work,” said WSDOT traffic engineer Mark Bandy. “Scheduling this type of work isn’t easy. It must be carefully coordinated with other regional construction projects and avoid weekends such as Seafair, the Bite of Seattle and Bellevue Arts Festival.”

On I-405, crews will replace the 50-year-old concrete panels in the two left lanes between SE Eighth and Main streets, the length of a dozen football fields. Later this summer they will replace panels in the two right lanes. They will also grind the concrete on certain sections of I-405. When the project is complete this fall, drivers will experience a smoother ride with improved traction.

On SR 520, bridge maintenance crews will inspect the floating bridge. The annual inspection, which includes testing, maintenance and repairs, must occur during calm weather. Eastside Transit and HOV Project construction crews will take advantage of the closure to install an 11-foot-in-diameter fish-friendly culvert — the project’s largest and deepest to date — beneath all lanes of SR 520 east of 108th Avenue NE.

Weekend closure details

I-405

• 10 p.m. Friday, July 12, to 5 a.m. Monday, July 15: Crews will close all lanes of northbound I-405 from SE Eighth Street to SR 520, as well as the eastbound and westbound I-90 ramps to northbound I-405. The exit to SE Eighth Street remains open, but drivers should expect heavy congestion and long delays.

SR 520

• 11 p.m. Friday, July 12, to 5 a.m. Monday, July 15: Crews will close both directions of SR 520 and all connected ramps between Montlake Boulevard in Seattle and I-405 in Bellevue. Two sections of SR 520 will remain open to traffic: I-5 to Montlake Boulevard and areas east of I-405.

Alternate routes 

• I-5
• I-90
• To reach downtown Bellevue: Take SE Eighth Street to 116th Avenue NE.
• To leave downtown Bellevue: Use NE Eighth Street to get to northbound I-405. Use NE 10th Street to get to eastbound SR 520. 
• Westbound SR 520 drivers can use southbound I-405 or 148th Avenue NE to travel south.
• I-90 drivers looking to head north on I-405 will be detoured to Bellevue Way and 148th Avenue SE.

Keeping traffic moving 
WSDOT will do everything possible to help keep traffic moving during the weekend lane closures and the Mariners games against the Los Angeles Angels: 

• Downtown Bellevue will be open for business with several alternate routes available.
• Additional Incident Response Teams will be on duty to clear incidents and stalled vehicles that worsen backups.
• The I-5 and I-90 express lanes hours of operation will be changed to accommodate weekend and Mariners traffic.

To reduce congestion, WSDOT is counting on drivers to:

• Delay or eliminate discretionary trips.
• Travel before 10 a.m. or after 7 p.m. on Saturday and Sunday.
• Allow at least one hour of extra time to reach destinations.
• Know detour routes before driving.
• Carpool, use public transportation or bike.
• Use Twitter to stay informed about traffic conditions. WSDOT will use the hashtag #Take5 to keep drivers informed during the closure. 
• Check WSDOT’s website for updated traffic information (see below).

Tools for drivers

• Seattle area traffic: www.wsdot.wa.gov/traffic/seattle
• Traffic cameras: www.wsdot.wa.gov/traffic
• Travel alerts: www.wsdot.wa.gov/traffic/trafficalerts
• Mobile apps for cell phones and other wireless devices: www.wsdot.com/Inform/mobile.htm
• Follow WSDOT on Twitter: twitter.com/WSDOT_traffic for Puget Sound traffic.
• Call 5-1-1 for traffic updates.
• Tune to highway advisory radio and watch electronic highway signs for information.

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 floating-bridge maintenance and the $306 million SR 520 Eastside Transit and HOV project.