Published July 12 2013
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 Saturday and Sunday.
The 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.
"These closures will significantly affect traffic around the greater Seattle/Bellevue area," WSDOT Traffic Engineer Mark Bandy said. "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.
Why are these closures necessary?
This weekend's work is vitally important for the maintenance and preservation of critical commuter and freight corridors.
- 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. 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.
Much of this work can't be performed in shorter, overnight closures. The concrete panels on I-405 need to cure for at least 10 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
From 10 p.m. Friday to 5 a.m. Monday, 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, with all lanes open by 5 a.m. The northbound I-405 exit to Southeast Eighth Street remains open through the weekend.
From 11 p.m. Friday to 5 a.m. Monday 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