Project Facts
- One new northbound lane from 112th Ave SE to SE 8th St, including reconfiguring the northbound freeway ramps from I-90
- One new southbound lane from SE 8th St to I-90
- Widens the existing northbound structure over Coal Creek Parkway
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 8th Street. A summary of planned improvements, scheduled for completion by late 2009:
Between 112th Ave SE and I-90
- Add a new northbound lane from 112th Ave SE to I-90
- Widen the existing northbound bridge over Coal Creek Parkway
Between I-90 and SE 8th
- 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 the end of 2008:
- New northbound lane between 112th Ave 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 by 50% 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
- Construction began in 2007 and will be complete by 2009.
- Construction began south of I-90 in summer 2007.
- Concrete pavement repair north of I-90 started in summer 2007.
- The south segment (112th Ave SE to I-90) will open to traffic by Fall 2008.
- Major construction will begin north of I-90 in early spring 2008.
- In fall 2009, the final project improvements will open to traffic.
Project history
- 5 percent footprint design began in July 2003
- Project design began in November 2004.
- Nickel Environmental Assessment began in January 2005.
- Environmental documentation and permitting competed in August 2006.
Public Involvement
Your thoughts and opinions are important to us. In addition to working closely with community councils and other local groups, the project team offers opportunities for public information and discussion. Please send the team an e-mail if you would like to be added to the project mailing list. You will be kept posted via e-mail on the project’s status and on further participation opportunities as the project progresses. Also, feel free to check this regularly updated web page for information. If you have comments or feedback please e-mail Steve Peer in the public information department for the I-405 Corridor Program at steve.peer@i405.wsdot.wa.gov.
Environmental Protection
WSDOT's I-405 Corridor Program team has completed the Environmental Assessment (EA) for this project which identifies the effects and mitigation of the project. The EA analysis covers up to 20 different disciplines, including noise, air quality, fish and wildlife, wetlands, and parks and recreation. Throughout the process to complete the EA, the I-405 Project Team designs the project to avoid or minimize effects to the environment whenever possible. The I-405 projects have benefits that improve the environment for people, wildlife, and habitat such as improved water quality, restored and enhanced stream and wetland habitat, and retrofitting of culverts to allow for fish passage.
Watershed-based planning
Building new lanes on I-405 will create additional surface water runoff that must be captured and cleaned before it reaches the stream system. This is typically accomplished with stormwater detention ponds; however, detention ponds are expensive to build and provide only the minimal required benefits. A better solution is a wetlands restoration site, which captures surface water upstream from the highway and detains it in a more natural environment. This maximizes benefits to the watershed at the same or less cost. This approach also analyzes the entire watershed, focusing on the whole rather than only at the sites of impact and minor adjustments at those sites
Please visit the WSDOT Environmental
Services Web site for more information.
Increasing safety is one of our priorities
Widening I-405 between 112th Ave SE and SE 8th St will reduce congestion and congestion-related accidents. The new northbound lane between 112th Ave SE and I-90 as well as the ramp meter at the northbound 112th Avenue SE on-ramp to I-405 will help reduce traffic congestion and improve safety. Congestion-related accidents – rear-end and side-swipe crashes – make up the largest percentage of accidents on I-405.
Will this project impact tribal resources?
This project will not affect tribal reservations lands. The I-405 Corridor Program works closely with tribes throughout the environmental process to ensure that the project avoids or minimizes any effects on archaeological sites, tribal traditional cultural properties, and natural resources. WSDOT will follow an Unanticipated Discovery Plan if unknown archaeological materials are encountered during construction.
At WSDOT we seek to address the concerns of the Tribes by using the process outlined in the WSDOT Tribal Consultation Policy adopted in 2003 by the Washington Transportation Commission as part of the WSDOT Centennial Accord Plan and Section 106 of The National Historic Preservation Act (NHPA).
The NHPA was enacted to address the publics concern that many of the nation's historic resources were being overlooked in the public works project process. NHPA Section 106 requires government agencies such as WSDOT to evaluate the impact of all government-funded construction projects. Under the act, agencies maintain their own preservation program, and are required to incorporate advice from historic preservation professionals.
For more information, visit our WSDOT Tribal Liaison Web page.
Financial Information
- Transportation 2003 Account (Nickel funding) - $180 million
- 2005 Gas Tax (Partnership Funding) - $20 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 - $202.3 million
How can I get more information?
Contact:
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