WSDOT Projects

 
View phased improvements to the I-405/I-90 interchange

Project Overview
The I-405, South Bellevue Widening Project, also known as the 112th Avenue SE to SE 8th Street Project, helps relieve congestion at one of the worst I-405 bottlenecks--the drive in and out of Bellevue.

In July 2007, Atkinson Construction, LLC, began widening I-405 within the city of Bellevue between 112th Avenue SE and SE Eighth Street. A summary of planned improvements, scheduled for completion by late 2009:

Between 112th Avenue SE and I-90

• Add a new northbound lane from 112th Avenue SE to I-90
• Widen the existing northbound bridge over Coal Creek Parkway

Between I-90 and SE 8th Street

• Build one new lane in each direction from I-90 to SE 8th Street
• Remove the Wilburton Tunnel
• Build a new, three-lane, southbound bridge over I-90
• Convert the existing southbound bridge over I-90 to carry the northbound HOV lane 

Why is WSDOT Improving I-405 in Bellevue?
WSDOT is constructing the South Bellevue Widening Project to improve one of the worst congestion chokepoints along the I-405 corridor. 

WSDOT plans to:

• Reduce congestion and increase travel speeds into and out of Bellevue by adding lanes
• Improve merging conditions and safety near I-90 by:
• Reconfiguring the northbound on-ramps from I-90 so traffic will not have to merge together before merging onto I-405
• Extending the southbound HOV lane on the west side of I-405 to I-90 so drivers have more time to merge
• Enhance wetlands and wildlife habitat by creating a wetland at Bellevue's Kelsey Creek Park to offset wetlands impacted by the project
• Improve wetland and stream habitat
  Improve water quality by treating highway stormwater runoff
• Reduce noise potential by testing new technologies, like a sound absorbent noise wall and quieter pavement
• Deliver improvements early by providing the following by early of 2009:
• New northbound lane between 112th Avenue SE and I-90
• Noise wall just north of I-90 on the east side of the freeway
• Kelsey Creek wetland improvements

The End Result
The South Bellevue Widening project will reduce congestion from Renton north into Bellevue and from Bellevue south to I-90. 

Project Benefits

• Congestion relief.  Increase general purpose capacity and improve traffic flow. 
• Safety.  Improve safety by improving traffic merge conditions and increasing freeway capacity.
• Environment.  Protect the environment by providing noise mitigation, creating a new stream channel, enhancing wetlands and wildlife habitat, and improving water quality by treating highway stormwater runoff.

What is the project timeline?

Construction timeline

• Spring 2007:  Construction begins.
• Summer 2007:  Construction begins south of I-90.
• Summer 2007:  Concrete pavement repair north of I-90 begins. 
• August 2008:  Remove Wilburton Tunnel.  
• November 2008:  Widen bridge over Coal Creek Pkwy to accomodate a new lane.
• December 2008: Build a new southbound bridge over I-90.
• January 2009: Add a new northbound lane from 112th Avenue SE to to I-90. Install new ramp meter, HOV bypass lane and second lane on northbound 112th Avenue SE on ramp.
• April 2009: Build a new southbound lane from SE Eighth Street to I-90 on the west side.
• Summer 2009: Extend existing HOV lane from SE Eighth Street to I-90. Build new noise walls.
• Fall 2009: The final project improvements will open to traffic. 

Project history

• July 2003:  5 percent footprint design began.
• November 2004:  Project design began.
• January 2005:  Nickel Environmental Assessment .
• August 2006:  Environmental documentation and permitting competed.
   

Financial Information
The information shown below reflects the current proposed project budget and schedule. The 2009 Legislature may consider changes to the transportation budget that may include adjustments to some project budgets and schedules.

• Transportation 2003 Account (Nickel funding) - $176.8 million
• 2005 Gas Tax (Partnership Funding) - $20.9 million
  In 2005, the Washington State Legislature provided $20 million towards this project by passing the Transportation Partnership Funding package.
• Other Agency Funds - $2.3 million: These funds are provided by the City of Bellevue and Federal sources.
• Total Funding Available From All Sources - $200 million

How can I get more information?
Contact:

Steve Peer
I-405 Corridor Program
600 - 108th Avenue NE
Suite 405
Bellevue, WA 98004
425-456-8624
steve.peer@i405.wsdot.wa.gov

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