Project Title & Location
SR 16 / I-5 - Westbound Nalley Valley, Tacoma.

Project Description
This project is the first of three projects to improve the SR 16/I-5 Nalley Valley interchange in Tacoma. The existing Nalley Valley bridge is too narrow to carry additional lanes and its unique structure prevents widening the existing bridge. Reconstructing Westbound SR 16 prepares for future HOV lanes and direct HOV ramps to SR 16 and I-5. This project sets the stage for rebuilding the Eastbound Nalley Valley bridge and the Sprague Avenue Interchange.

Contractor/Consultant
Project not yet advertised or awarded.

Recent Progress

Design: Completed a geometric evaluation of the interchange. Finished investigation of existing drainage system in Nalley Valley and along Sprague Avenue. Submitted updated bridge site data packages.

Construction: Planning for over-the-shoulder review of the design work.

Design Construction Impacts

Environmental Impacts / Compliance

NEPA re-evaluation - Assessing potential mitigations sites for 0.1 AC of wetland impact; Nalley Valley Viaduct has been identified as a possible candidate for the Register of Historic Bridges, may need to do a supplement to the Environmental Assessment; Air and Noise analysis is being re-analyzed for 2030 traffic numbers.  

Impacts to Traffic
Long-term closure of Sprague Avenue, short-term closures of southbound  I-5 to 38th Street off-ramp and 38th Street to westbound SR  16 on-ramp. There will also be night-time closures on I-5, Center Street and South Tacoma Way for girder placement and other construction work.

Planned vs. Actual Expenditures
(Total Project Cost)

Nickel funds included in above costs

2005 Transportation Partnership Account