I-5 - SR 510 Interchange - Reconstruct Interchange

Project news

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  • WSDOT will build a Diverging Diamond Interchange at I-5 and SR 510 in Lacey. It will be the first Diverging Diamond Interchange, also called a DDI, built in the state of Washington. 
  • Learn more on the linked YouTube video.
  • Funding for this project was included in the Connecting Washington Transportation Revenue Package.


Why is WSDOT reconstructing the I-5 and SR 510 interchange in Lacey?
WSDOT is accommodating planned regional growth adjacent to the interchange. Traffic modeling shows that a Diverging Diamond Interchange, the first of its kind in the state, will accommodate future growth in the area. 

The End Result
The improvements will accommodate economic development for the Hawks Prairie community. This project will expand on previous improvements that have been implemented by the City of Lacey and WSDOT.

Project Benefits
DDIs are a proven way to move more people and reduce the potential for collisions by reducing conflict points.

What is the project timeline?

  • Late 2015 – Finalize project scope and determine project delivery method.
  • 2016 – Acquire right-of-way and environmental permits.
  • Early 2016 – Begin preliminary design.
  • Early 2017 – Begin final design.
  • Spring 2018 - Project advertised for competitive bidding.
  • Summer 2018 – Begin construction.
  • Summer 2020 – Complete construction.


Financial Data for PIN BL1100110
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $0
CWA $72,000
Total $72,000


How can I get more information?

Kim Mueller
WSDOT Project Engineer

Claudia Bingham Baker
Olympic Region Communications Manager