Work begins on the SR 411 Cowlitz River Bridge in Castle Rock Sept. 20

Month-long utility work needed before year-long bridge replacement

CASTLE ROCK – Beginning Monday, Sept. 19, Castle Rock travelers will notice work underway on the State Route 411 Cowlitz River Bridge as initial month-long utility work begins to prepare for the eventual bridge deck replacement project. The month-long utility work will include flaggers to help keep traffic moving across the bridge.

Once the utility work is completed, the Washington State Department of Transportation will have contractor crews undertake the year-long work to replace and widen the concrete bridge deck.

In addition to the new bridge deck, work includes a new, wider sidewalk on the north side of the bridge, replacing and upgrading the city of Castle Rock’s water line that runs under the bridge deck and new pedestrian- and bicycle-friendly traffic barriers to add greater separation and protection. All of this work helps extend the useful life of the almost 60-year-old bridge.

What travelers should expect

  • Beginning Monday, Sept. 19, and continuing for up to one month, the SR 411 Cowlitz River Bridge will be intermittently reduced to a single lane of traffic during daytime hours for utility relocation. Flaggers will be located on either side of the bridge to alternate traffic and minimize delays to the traveling public. No nighttime lane closures are scheduled, and all lanes of the bridge will be opened to traffic by the evening hours.
  • Once the utility work is completed the deck replacement portion of this work is expected to begin later this fall. Travelers can expect around-the-clock single lane closures and delays up to 15 minutes at a time during daytime and nighttime hours as well as a few weekends of total closures.
  • WSDOT is working closely with the school district to reduce and minimize delays during peak school travel times.
  • Travelers are encouraged to plan ahead and take alternate routes by traveling south along SR 411 to Lexington Bridge Drive or traveling north on SR 411 to SR 506.

WSDOT will announce the dates of the year-long bridge deck replacement project once they are finalized.

Slow down – lives are on the line. 

In 2023, speeding continued to be a top reason for work zone crashes.

Even one life lost is too many.

Fatal work zone crashes doubled in 2023 - Washington had 10 fatal work zone crashes on state roads.

It's in EVERYONE’S best interest.

95% of people hurt in work zones are drivers, their passengers or passing pedestrians, not just our road crews.