I-405 - Renton to Bellevue Widening and Express Toll Lanes - Tukwila to I-90 - Environmental Assessment - Overview

Graphics showing the major features of the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project include adding new capacity to create a two-lane express toll lane system between SR 167 in Renton and Northeast Sixth Street in Bellevue. In addition, there will be structural, trail and transit improvements within this 11.9-mile section of I-405 from the I-5/I-405 interchange in Tukwila to about a mile north of the I-90/I-405 interchange in Bellevue.The Environmental Assessment (pdf 13.45 mb) for the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project studies the roadway, structural, trail and transit improvements for an 11.9-mile section of I-405 from the I-5/I-405 interchange in Tukwila (Milepost 0.0) to about a mile north of the I-90/I-405 interchange in Bellevue (Milepost 11.9).

Project context
WSDOT plans to build the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project as part of a larger construction contract known as the I-405 Renton to Bellevue Widening and Express Toll Lanes Project, which extends south to I-5 in Tukwila. 

Major project features

  • Implementing two express toll lanes in each direction from north of the I-90 interchange to SR 167.
  • Reconfiguring the southbound I-405 ramp to eastbound I-90 from one to two lanes.
  • Building a new bridge for southbound I-405 traffic at the Coal Creek Parkway SE interchange.
  • Replacing the I-405 bridge and rebuilding the 112th Ave SE interchange, installing potential inline stations and reconfiguring Newport Hills Park and Ride lot. (Some improvements may be constructed after 2024, depending on when allocated funds for these elements become available.)
  • Relocating 2.5-mile section of the Lake Washington Trail to the Eastside Rail Corridor.
  • Constructing new fish passage crossings.
  • Constructing or relocating noise walls. 
  • Rebuilding the NE 44th Street interchange, installing direct access ramps and inline transit stations for I-405 Bus Rapid Transit, and adding a Park and Ride lot. (Improvements would be built, but may be built by Sound Transit or others.)
  • Replacing the I-405 bridge over May Creek.
  • Widening the northbound and southbound I-405 bridges at Sunset Boulevard North.
  • Rebuilding the Renton Avenue Bridge and the Cedar Avenue Bridge.

Purpose of the project and projected benefits:

  • Providing a reliable trip choice for I-405 users
  • Increasing vehicle capacity and person throughput
  • Improving access for I-405 users
  • Improving reliability for transit
  • Reducing project-wide congestion
  • Improving safety performances

Continue reading about the key findings of the Environmental Assessment.