I-5/SR 16 Nalley Valley interchange in 2013, after both the
Westbound and
Eastbound jobs are complete.

Nalley Valley interchange in 2022. The final connections are complete between HOV lanes on I-5 and SR 16. The
enhanced photo enlargement (pdf 1.48 MB) labels the roadways to show how traffic will move between I-5 and SR 16.
April 2013
Curious how the Sprague T interchange will work?
Check out this .wmv file showing a simulation of SR 16 through the Nalley Valley after we have completed all our work. The animation shows all of changes we're making, and the "Sprague T" ramp is easy to spot. It is the ramp that will accommodate traffic going from eastbound SR 16 to Sprague Avenue, and traffic going from Sprague Avenue to I-5.
Half of the "Sprague T" opened to traffic in June 2011, providing access from eastbound SR 16 to Sprague Avenue. The other half (actually two ramps) will be completed in 2014 and will provide access from southbound Sprague Avenue to northbound and southbound I-5.
The rest of this page discusses the third and final project to improve the I-5/SR 16 interchange. The third project, which will build an HOV facility through the Nalley Valley and direct-connect HOV ramps between HOV lanes on I-5 and HOV lanes on SR 16, is scheduled to be constructed between 2020 and 2022.
Design on the project will begin around 2017. Why so far into the future? Because, although the project is funded, monies needed for design and construction activities will not be available until then.
Why is WSDOT
building HOV roadways and HOV direct-access ramps as part of a newly-expanded I-5/SR 16 Nalley Valley interchange?
To increase safety, improve mobility and reduce congestion, WSDOT is rebuilding the entire I-5/SR 16 Nalley Valley interchange. The original Nalley Valley interchange was too narrow to carry additional lanes and the unique structure-type prevented widening.
Reconstruction of the interchange is staged to keep people and goods moving. The first two stages of work rebuild the westbound and eastbound Nalley Valley viaduct bridges. This last stage cannot be built until the other two are complete.
The new westbound viaduct and associated westbound ramps are already built and they opened to traffic in June, 2011. Eastbound construction is now in progress and will continue through spring 2014.
In the third project, not only will WSDOT build new HOV bridges and ramps, crews will also rebuild and realign northbound and southbound I-5 approaching SR 16.
This project is one of several that make up a larger program to reduce congestion, improve safety and add HOV lanes in Pierce County. Learn more about the overall Tacoma/Pierce County HOV Program.
The End Result
The HOV Connector project will build new bridge structures and direct-access ramps to connect I-5 HOV lanes to SR 16 HOV lanes. These structures will be limited solely to HOV traffic, and will create the last HOV link within a core HOV system that will stretch from Gig Harbor to Everett. A significant amount of construction will also occur on northbound and southbound I-5 while crews realign it for better traffic flow.
Project Benefits
The HOV Connector project has numerous benefits, including:
Traffic Operations
- Builds direct-access HOV ramps connecting I-5 HOV lanes with SR 16 HOV lanes
- Adds capacity and improves traffic flow
- Reduces conflicting movements and weaving areas
Environmental
- Improves stormwater treatment
Safety
- Widens shoulders
- Improves lighting
- Improves ramp alignments and curves
What is the project timeline?
2017 - Design work to begin
2020 - Construction to begin
2022 - Construction ends; HOV facilities at I-5/SR 16 interchange open to traffic.
This project and two more in the Tacoma/Pierce County HOV Program completely rebuild the Nalley Valley interchange. Those projects and more make up the entire Tacoma/Pierce County HOV Program. Learn more!
Financial Information
Project signage will reflect the cost of construction engineering, project bid award and sales tax.
- 2005 Gas Tax (Partnership Funding) - $215.6 million
- Federal - $1.6 million
- State - $0.1 million
- Total Funding Available From All Sources - $217.3 million
How can I get more information?
Contact:
Questions about the Tacoma/Pierce County HOV Program:
Claudia Bingham Baker
Communications Manager
WSDOT Olympic Region
5720 Capitol Boulevard SE
Tumwater, WA 98501
Phone: 360-357-2789
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