I-5 - SR 16 Realignment - HOV Structure and Connections

Project news

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 rebuilt the westbound and eastbound Nalley Valley viaduct bridges. This last stage could not be built until the other two were complete.

The new westbound viaduct and associated westbound ramps opened to traffic in June, 2011.  Eastbound construction reached its last major milestone August, 2014 when crews opened two new ramps from South Sprague Avenue to northbound and southbound Interstate 5.

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.

Needs & 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


  • Improves stormwater treatment


  • Widens shoulders
  • Improves lighting
  • Improves ramp alignments and curves


  • Late 2015 - Request for qualifications.
  • Early 2016 - Request for proposals.
  • Mid 2016 - Design-build contract awarded to Skanska and WSP/Parsons Brinckerhoff design build team.
  • Winter 2017 - Begin construction.
  • Fall 2019 - Contractor anticipates project operationally complete.
  • 2020 - Construction ends; HOV facilities at I-5/SR 16 interchange are ready to 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 Data for PIN 300566A
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $161,017
Pre-Existing Funds (PEF) $123
CWA $0
Total $161,141


Gaius Sanoy
WSDOT Project Manager

Cara Mitchell
WSDOT Olympic Region Media Relations

area map thumbnail

Nalley Valley in 2013
I-5/SR 16 Nalley Valley interchange in 2014, after both the Westbound and Eastbound jobs are complete.

Nalley Valley Interchange complete
Nalley Valley interchange in 2020. The final connections are complete between HOV lanes on I-5 and SR 16. The enhanced photo enlargement (pdf 1.5 MB) labels the roadways to show how traffic will move between I-5 and SR 16.