I-5 - Chamber Way Overpass

Project news

  • Detour Bridge Removal Thursday, Nov. 1 to the morning of Friday, Nov. 2: Starting at 9 p.m., a single lane in both directions of I-5 will close, with all lanes of I-5 shifted to detour to the Chamber Way off- and on-ramps from 11 p.m. to 5 a.m., for detour bridge removal work. During the I-5 detour, Chamber Way will close between Louisiana Avenue and State Avenue from 8 p.m. to 7 a.m., to allow a free flow of interstate traffic through the intersections.
  • An additional nighttime closure of Chamber Way will be necessary for final striping work. This work is highly weather dependent and has not yet been scheduled. 
  • The new Chamber Way overpass opened to traffic on Saturday, Oct. 20.
  • For additional traffic impacts, check our current travel conditions.
  • View project information from the July 26 Open House:
  • Design-build contract awarded to Quigg Bros., Inc. of Aberdeen on May 4, 2017.

The Washington State Department of Transportation will replace the existing I-5 Chamber Way overpass with a taller, wider structure.

On the morning of Friday, July 22, 2016, a semi-truck hauling a pair of excavators hit a portion of the Chamber Way bridge that spans over southbound I-5 in Chehalis, causing significant structural damage.

For the safety of the traveling public, the damaged span was demolished and a temporary bridge is currently in place.

Why is WSDOT building a new Chamber Way overpass?
The existing overpass was built in 1958 and does not meet modern design standards. The Chamber Way overpass is a two lane bridge spanning across the interstate, and is only 14 feet 8 inches above I-5.

WSDOT demolished a portion of the bridge that was damaged by an oversized load and installed a temporary bridge in the summer of 2016.

The End Result
A wider, taller overpass will keep people in Chehalis connected between a vibrant commercial center west of I-5 and the city center. 

The new overpass will be incorporated into a future project that will add improvements to I-5 and modify the adjacent intersections.

Needs & benefits

Safety - The new overpass will replace the existing structure and temporary bridge that is currently in place.

Mobility - Chamber Way will be widened across I-5, with improved bike and pedestrian access.


  • Spring 2017 - Design work begins
  • July 2017 - Construction begins
  • Fall 2017 - Chamber Way traffic will shift to temporary detour bridge
  • Fall 2018 - Scheduled completion


Financial Data for PIN 400516E
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $5,116
CWA $10,500
Total $15,616


Celeste Dimichina
WSDOT communications

Susan Fell
Project Engineer