SR 520 to close from Montlake Boulevard to I-405 from Aug. 26-29

Travelers heading to a video game convention, sporting events and a 10k race in Seattle this coming weekend can expect major traffic congestion as construction crews close State Route 520.

Travelers heading to a video game convention, sporting events and a 10k race in Seattle this coming weekend can expect major traffic congestion as construction crews close State Route 520.

SR 520 will close between Montlake Boulevard in Seattle and Interstate 405 in Bellevue starting at 11 p.m. Friday night and reopen at 5 a.m. Monday morning.

The heaviest traffic is expected midday Saturday and Sunday on Interstates 5 and 90 heading into Seattle, and on I-405 approaching I-90. The express lane schedules will change this weekend on I-5 and I-90 to help improve traffic flow.

“Crews need this weekend to finish major culvert and stream work before migrating fish return this fall,” said Brian Dobbins, WSDOT construction engineer for the SR 520 Eastside Transit and HOV Project. “Traffic conditions during these construction closures depend on drivers. We all need people to consider their options – leave early, take a differentroute, find a carpool buddy, take the bus or keep activities close to home.”

Several big events are expected to draw tens of thousands of people to Seattle this weekend:

  1. The three-day PAX Prime 2011 video game festival is at the Convention Center Friday through Sunday.
  2. The Seattle Marathon is holding a 10k race to and from Seattle Center Saturday morning, closing the northbound lanes of SR 99 from the Battery Street Tunnel to the Aurora Bridge from 7:30-11 a.m., as well as other local streets.
  3. Sounders FC plays at 1 p.m. Saturday at CenturyLink Field.
  4. Mariners games are 7:10 p.m. Saturday and 1:10 p.m. Sunday at Safeco Field.
  5. The Seattle Storm plays at 6 p.m. Sunday at KeyArena.

Starting late Friday night, crews working on SR 520 will quickly dig a trench across all lanes near Yarrow Point to install the 230-foot-long steel culvert. The new culvert replaces a smaller structure that blocked migrating fish. Environmental permits only allow WSDOT to work in streams through the end of September to avoid harming migrating fish. This is the third of six new culverts that will cross under SR 520, improving access to habitat for salmon and a variety of fish.

Additionally, work near Evergreen Point Road will result in a traffic shift on SR 520 when the highway reopens Monday morning. Eastbound and westbound drivers will be required to follow a slight jog to the right around a new median work zone for construction of a landscaped lid above the highway.

Closure details

SR 520

All on-ramps to SR 520 between Montlake Boulevard in Seattle and I-405 in Bellevue will close at 11 p.m. Friday, Aug. 26. All SR 520 ramps in the construction zone will remain closed during the weekend, except for the 108th Avenue Northeast on-ramp to eastbound SR 520.

The SR 520 mainline – all lanes in both directions between Montlake Boulevard in Seattle and I-405 in Bellevue – will close from 11 p.m. Friday, Aug. 26, to 5 a.m. Monday, August 29.