Spokane St Swing Bridge (low bridge) closing April 20-29 to people driving, walking, and biking – What to expect and how you can prepare.

Cars and trucks travel on the Spokane St Swing Bridge (low bridge) over the Duwamish Waterway. Photo: SDOT

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Editor’s Note: During April 20-29, we completed essential updates to the 30-year-old communication and control system for the Spokane St Swing Bridge. These upgrades include new computers to control bridge operations and activate safety gates. We also improved communication lines connecting the control tower and moving parts across the Duwamish Waterway. This significant milestone, part of the Spokane St Swing Bridge Rehabilitation Program, ensures the bridge’s long-term reliability. Learn more about these updates on the X platform:

At-a-glance:

We’re closing the Spokane St Swing Bridge (low bridge) from Saturday, April 20 at 6 AM until Monday morning, April 29, planned to reopen by 5 AM.
The closure is needed to complete upgrades to the bridge’s control and communications system, as part of the overall Spokane St Swing Bridge Rehabilitation Program.
Travelers will need to detour to other routes detailed in this blog post. The West Seattle Bridge (high bridge) will remain open during the low bridge closure.
People who use the bridge are eligible for support to take transit including the bus and West Seattle Water Taxi through the Transit Go Ticket app, using rewards code LOWBRIDGE24 beginning on April 20, 2024. Detailed instructions on how to use this support can be found here.
To stay informed, we encourage you to sign up for email updates.

From April 20 to April 29, our crews will temporarily close the Spokane St Swing Bridge (low bridge) to all people driving, biking, walking, and rolling. The closure is needed to reroute control tower wires from the West Seattle Bridge to a new conduit beneath the Duwamish Waterway and replace the control system. We appreciate your patience as we complete this necessary work and hope this blog post provides resources that help you get around during the closure.

Editor’s Note – April 15, 2024: We updated this blog post to reflect updated low bridge closure dates. The closure was originally scheduled to begin on April 19, but we realized we could accomplish the work planned that day without closing the bridge until April 20.

Work taking place

The next step of the Spokane St Swing Bridge Rehabilitation Program is to upgrade the control system we use to open and close the low bridge. The original system of logic controllers, push buttons, switches, and wiring is over 30 years old. This system controls the machinery that lifts and swings the spans and activates the gates that prevent traffic and people from crossing when the low bridge is open. As part of this project the communication lines that connect the computers, control tower, and the moving parts to one another will also be replaced.

During the closure, crews will reroute the wires connecting the control tower with the hydraulic system that opens and closes the bridge off the high bridge to a new conduit under the West Duwamish Waterway.

Graphic showing the existing communications system running along the West Seattle Bridge (high bridge) today. — *The communications system currently runs along the West Seattle Bridge. Graphic: SDOT.*

Graphic showing what communication lines will run below the Duwamish Waterway after this work is completed. — *When this work is complete, the communication line will run beneath the Duwamish Waterway. Graphic: SDOT*

How to get around during the closure

While you will not be able to travel using the low bridge, we have compiled a list of other options to reach your destinations during the closure.

Closure location map

Map graphic showing the location of the low bridge closure in an orange line, with the West Seattle Bridge (high bridge) remaining open with a green line. A blue dotted line shows access to Harbor Island. — *The low bridge will be fully closed, but the West Seattle Bridge (high bridge) will remain open. Graphic: SDOT*

Riding the bus

The bus provides a reliable option to get to destinations on both sides of the Duwamish Waterway.
Buses travel via the West Seattle Bridge (high bridge) and can be used by people walking, riding bikes, and in wheelchairs.
Buses are the fastest way to get across the Duwamish Waterway without driving.
We encourage you to visit King County Metro’s trip planner page to find the latest bus route and schedule details for your trip.

Riding the Water Taxi

King County operates the West Seattle Water Taxi, which provides direct service from West Seattle to downtown Seattle.
Their large vessels can store up to 26 bikes at a time.

Please note: We are offering support to people who would like to take transit during the closure with a rewards code through the TransitGo app. Detailed instructions on how to use this support can be found here.

Walking, biking, and rolling

People walking, biking, and rolling will not be able to use the low bridge to cross the Duwamish Waterway during the closure.
There are several other routes to get around the closure by bike, including West Marginal Way SW where we recently added permanent safety barriers to the protected bike lane. Check out our Bike Map to see where there are bike facilities.
Transit is another reliable option for people walking and rolling to use during the closure.

Driving or carpooling on the West Seattle Bridge (high bridge)

The high bridge remains open to drivers and offers a direct connection for many travelers to reach their destinations.
There are currently no restrictions on vehicle access.
This bridge is not accessible to pedestrians or people biking.

Freight and business access to Harbor Island and Terminal 5

Truck drivers, Port workers, and other people who need to access Harbor Island and Terminal 5 are still able to do so, though they need to be aware of the route before making their trip.
Access to Harbor Island remains available from the east via SW Spokane St, before reaching the Spokane St Swing Bridge.
For those traveling to Terminal 5 from the east, please use alternate routes, such as the West Seattle Bridge (high bridge).

Support for travelers during the closure

To support people impacted by the closure, and to help make transit easier to access, we’ve partnered with King County Metro to give people an opportunity to take transit including the bus and the West Seattle Water Taxi with Transit Go Tickets throughout the closure.

This offer will provide a daily round trip over the Duwamish while the bridge is closed. To access the offer, follow the directions below using the Transit Go Ticket app and rewards code LOWBRIDGE24. The fares are funded by the Seattle Transit Measure, which was passed by voters in 2020.

How to access bus and water taxi credits during the low bridge closure:

Download the Transit Go Ticket app and create an account.
Click on “Rewards,” select “More,” then tap “Rewards Code” and enter code LOWBRIDGE24.  
Tap “Claim” and then the “Redeem” tab; you will see “Low Bridge Closure” tickets available for King County Metro Bus or King County Water Taxi.
Select the ticket of your choice and tap “Redeem for Free” and “View Ticket.” You can see your tickets any time under “Use”.
When you are ready to ride, tap on your ticket and then “Activate”; show it to your transit operator.
Visit “Redeem” to follow these steps again for your reverse trip.
Once you’ve used this code, it will allow you to redeem two tickets for each further day the low bridge is closed (while supplies last). Just visit the Redeem tab in Rewards for those additional tickets.

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