CANCELED Northbound I-405 to close from 11p.m. Friday, Sept. 23 to 4a.m. Monday, Sept. 26


Next Monday, two new downtown on-ramps will eliminate Bellevue's infamous I-405 traffic tussle, making it easier and safer for motorists to get to SR 520.

State Department of Transportation (WSDOT) crews must close the northbound lanes of Interstate 405 between Northeast Eighth Street in Bellevue and SR 520, from 11 p.m., Friday, Sept. 23, until 4 a.m., Monday, Sept. 26. Several northbound ramps in Bellevue will also be closed. Northbound drivers will still be able to access downtown Bellevue, and southbound I-405 will not be affected.



We will build new multi-level "braided" ramps to separate vehicles entering and exiting northbound I-405 between NE 8th Street and SR 520 in Bellevue. Here's a diagram of how the "braided" ramps work to separate traffic. This project will add a bypass lane for I-405 traffic headed eastbound to SR 520. A new ramp from the NE 10th Street overpass will give drivers direct access to SR 520 from downtown Bellevue.

As part of our corridor Master Plan, our different projects fit together like puzzle pieces. The NE 10th Street bridge will eventually act as an anchor for ramps connecting downtown Bellevue directly to SR 520 as part of the Bellevue Braids project. Some of the bridge railings on the new bridge will be removed when the ramp is connected to the bridge and then reused on other projects or used as replacement parts if the railings become damaged.

Why is WSDOT building this project? This area experiences up to eight hours of traffic congestion a day. The new improvements will reduce congestion on I-405 caused by northbound traffic exiting to SR 520 and entering from NE Eighth Street. The project also eliminates weave congestion on SR 520 between traffic entering from I-405 and exiting to 124th Avenue NE.

The End Result The completion of this project improves safety by eliminating traffic weaves for motorists on northbound I-405 and eastbound SR 520 between NE Eighth Street and 124th Avenue NE.

Project Benefits

  • Safety: Reduces congestion-related collisions. In addition, this project will enhance local pedestrian and bicycle access with a longer, wider NE 12th Street bridge.
  • Congestion relief:
  • Improves traffic flow by addressing back-ups on the highest volume ramp on the I-405 corridor: northbound I-405 to eastbound SR 520.
  • Improves congestion on eastbound SR 520 in the vicinity of the 124th Avenue NE off-ramp, leading into the busy Northup business district in Bellevue.
  • Reduces congestion on NE 8th Street, improving local access, circulation and operations in downtown Bellevue.
  • Environment: WSDOT's I-405 Corridor Program team is designing the northbound NE 8th Street to SR 520 Improvement Project to avoid and minimize impacts to the environment.