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I-5 - Union, Steamboat, and Ebey Slough Bridges - Special Bridge Repair

Ths project is in the construction phase.
A small map showing the location of the Union, Steamboat and Ebey Slough bridges between Everett and Marysville.
See a larger version of the map
showing the locations of the Union, Steamboat and Ebey Slough Bridges.

This photo shows a failing expansion joint on the northbound I-5 Steamboat Slough Bridge between Everett and Marysville.
A worn and deteriorating expansion joint on the northbound I-5 Steamboat Slough Bridge.

This photo shows a failing expansion joint on the northbound I-5 Ebey Slough Bridge between Everett and Marysville.
A broken expansion joint on the northbound I-5 Ebey Slough Bridge. More photos
 on the website.

Photos on Flickr.


February 2017

  • This project is now complete.
  • Thank you: WSDOT thanks drivers for their patience and understanding during this bridge preservation project.

Crews replaced a total of 41 aging expansion joints on the Interstate 5 Ebey Slough, Union Slough and Steamboat Slough bridges between Everett and Marysville.

Why is WSDOT replacing 41 expansion joints on the bridges?

The bridge expansion joints ranged in age from 20 to 30 years old. They exceeded their useful lifespan and are began to fail. They deteriorated to the point that replacing them was necessary to keep the bridges in good working order. Ongoing problems with the expansion joints included:

  • Broken and missing steel bars and panels.
  • Protruding or missing bolts.
  • Torn rubber seals that no longer prevent water from seeping into the expansion joints. This can cause additional deterioration to the joint and the bridge.
  • Missing concrete around many of the expansion joints. 

Thousands of commuters, freight haulers and travelers use I-5 every day. The interstate is the backbone of the Washington economy and it's vital that we keep people and goods moving on it. Replacing the expansion joints protect and preserve the bridges, maintain traffic flow and enhance the economy. These are vital elements in Results WSDOT (pdf 149 kb), the agency's strategic plan for 2014-2017. 

Washington's highway infrastructure is aging. Repairing and replacing components such as these bridge joints helps extend the lifespan of these bridges.

What would happens if they weren't replaced?

Bridge damage or failure

  • The odds increased that the expansion joints would fail leading to severe damage of the bridges. Damaged and failed joints can cause a bridge to bend, crack, or even collapse. Replacing the expansion joints reduced the likelihood of unexpected lane or bridge closures that would bring traffic to a standstill while lengthy emergency repairs are performed.

Safety hazard

  • Deteriorating bridge expansion joints pose a safety hazard to drivers. They can unexpectedly pop up into traffic, damaging vehicles and cause drivers to swerve to avoid them, increasing the risk of collisions.  

What do expansion joints do?
Expansion joints are critical to how a bridge functions. They allow the concrete sections of a bridge to expand and contract as the temperature changes and traffic loads vary.

The three bridges have three different types of expansion joints in various locations:

What should drivers expect?
WSDOT carefully reviewed the options for completing this work in an efficient, cost-effective manner while reducing the impact to drivers as much as possible.

Completing this work required a combination of overnight and weekend lane reductions. The larger expansion joints required around-the-clock lane reductions for eight weekends.

We are working closely with Snohomish County, the cities of Everett, Marysville and Arlington, the Tulalip Tribes and Community Transit to coordinate construction projects and special events.

What are the challenges we faced?

  • Construction coordination - Partner agencies have important projects to complete as well: 
    • The Tulalip Tribes are working on an expansion of the I-5/116th Street Northeast interchange
    • Arlington, Marysville and Snohomish County also have projects.
    • The agencies are closely examining construction plans and schedules to reduce conflicts as much as possible. 
  • Weather - Severe cold or heavy rain forced construction delays.
  • Public outreach - This is a large project with significant impacts to traffic. I-5 through this area attracts many travelers from throughout the region and even into Canada. A widespread outreach effort and utilizing the resources of partner agencies was required to inform as many people as possible.

The End Result
Forty-one aging expansion joints on the Ebey Slough, Steamboat Slough and Union Slough bridges were replaced with new expansion joints, expected to last for up to 25 years. These improvements will help maintain the bridges' structural integrity and improve driver safety.

Project Benefits

  • Preservation of infrastructure - New expansion joints will preserve the structural integrity of these bridges and extend their lifespans. The bridges are a critical part of the I-5 corridor.
  • Keeping traffic moving - Replacing expansion joints reduces the risk of joint failure, allowing traffic to keep moving on this bridges.
  • Maintenance - New expansion joints reduce the need for emergency repairs which can inconvenience drivers, particularly if lanes need to be closed during peak commute times.
  • Safety - New expansion joints are less likely to come loose in heavy traffic. Expansion joints popping up into traffic lanes can damage vehicles and contribute to collisions as drivers try to avoid the expansion joint.

What is the project timeline?

  • May 2015 - The project will be advertised for competitive bidding.
  • June 2015 - The project was awarded to PCL Civil Constructors.
  • Summer 2015 - Construction work began.
  • Fall 2015 - Work is complete on the Union Slough bridge.
  • Winter 2016 - Weekend lane reductions begin.
  • June 2016 - project is scheduled for completion.

Financial Information

Financial Data for PIN 100512S
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $6,145
CWA $0
Total $6,145

Project signage will reflect the cost of construction engineering, project bid award and sales tax.

How can I get more information?
Hung Huynh
WSDOT project engineer - design

Mark Sawyer
WSDOT project engineer - construction

Kris Olsen
WSDOT communications

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