8th Ave NW Bridge Seismic Improvements Project

Updated: February 10, 2022

What's happening now?

There is an ongoing general strike of concrete drivers and concrete plant workers in the Seattle area that involves companies that supply us with concrete for our many active construction projects.

This is a challenge and SDOT supports a fair resolution among the parties. In the near term, we're continuing other project work at the site and behind the scenes and will be sure to share more about the strike outcome and any impacts to this project as information becomes available. SDOT remains hopeful that this issue will be resolved soon. 

Construction began on January 10, 2022 and is anticipated to last approximately 5-6 months.

To complete the work as safely and efficiently as possible the bridge will be closed to all traffic for the duration of construction. The planned traffic detour route will use nearby 3rd Ave NW to NW 137th St to access homes north of the 8th Ave NW bridge.  We understand this closure will impact everyone who uses the bridge regularly and will do what we can to minimize impacts.

A map of the detour route for upcoming work.

We currently anticipate the following construction impacts:

  • Work in the public right-of-way near your home or business
  • A temporary full bridge closure with detours for people walking, biking, and driving
  • Occasional traffic or lane restrictions, including side street closures
  • Temporary on-street parking restrictions, with "no park" signs placed 72 hours in advance
  • Detours for people walking, biking, and driving to get you safely around work zones
  • Typical construction equipment, materials, noise, dust, and activity in the work area
  • Typical weekday work hours are 7 AM - 5 PM, Monday through Friday
To stay up to date with the latest project information, sign up to join the project listserv. 

Project overview

Earthquakes could have a detrimental effect on Seattle's infrastructure. To address seismic risks to city infrastructure, the City of Seattle established a bridge seismic retrofit program to assess the seismic vulnerability of the City's bridges and to prioritize limited funding to reduce this transportation infrastructure vulnerability. 

As part of the Levy to Move Seattle, 16 bridges were selected for seismic retrofits, including the 8th Ave NW Bridge. The 8th Ave NW Bridge is an older bridge constructed in 1950 prior to the modernization of the seismic design code. Spanning a forested ravine and connecting different parts of the Broadview neighborhood, it carries both vehicular and pedestrian traffic. 

The planned seismic retrofits to the 8th Ave NW Bridge include several modifications to seismically strengthen existing bridge components and reduce the bridge's vulnerability to earthquakes. There will be construction equipment, noise, dust, and possible detours for the duration of the project to maintain a safe separation between people and the work site. 

Project Map

Map of 8th Ave NW Bridge

Schedule and construction*

  30% Design   Complete
  60% Design   Complete
  Final Design   Complete
  Construction begins   January 2022


*The schedule is subject to change. 

Once construction begins it is scheduled to last approximately 5-6 months. Please note this work is weather dependent.


The total project estimate is $3 million and is currently funded by a FEMA grant and through the Levy to Move Seattle. Approved by voters in 2015, the 9-year, $930 million Levy to Move Seattle provides funding to improve safety for all travelers, maintain our streets and bridges, and invest in reliable, affordable travel options for a growing city.

Get involved

We're committed to keeping you informed and working with neighbors to limit construction impacts to the extent feasible. Here are some more ways to get information about the project: