The Washington State Department of Transportation (WSDOT) announced on Monday, Jan. 11, 2021 that work on the southbound SR 99 Duwamish River Bridge – aka the First Avenue South bridge – is projected to begin in February.

Massana Construction Inc. of Gig Harbor’s will do the work, with a bid of ~$380,000.

This will likely cause traffic disruptions around and over the bridge.

“With the West Seattle Bridge closed, we understand how important the SR 99 Duwamish River Bridge is to people who travel to or from West Seattle,” WSDOT said. “We are working closely with the Seattle Department of Transportation as we plan for and schedule repairs.”

Here’s more from WSDOT:

Repairs coming
When this work begins it will only affect southbound SR 99; the northbound lanes will remain open at all times. While we’re working, several alternative routes are available.

Alternative routes during southbound SR 99 Duwamish River Bridge work
When we reduce the southbound SR 99 Duwamish River Bridge to two lanes, people have several options.

Our contract allows for up to 15 nights of work. At the start of the project we will need to close all lanes of southbound SR 99 between 10 p.m. and 5 a.m. for one night so our contractor can set up their equipment. Travelers can expect about three weeks with the southbound bridge reduced to two lanes. We’ll also need a full overnight southbound closure at the end of the project to remove equipment.

During the work, Massana’s crews will replace bearing pads, which allow the structure to flex and move with weather and traffic conditions. They’ll also do some steel repair and concrete bridge deck repairs. To accommodate this, crews will shift traffic to the one side of the bridge first, then move traffic to the other side to finish.

Why we’re working now
The bearing pads – masonry pads that the girder rests on – were part of the initial construction when the southbound SR 99 Duwamish River Bridge opened in 1996. These pads are worn out and need to be replaced. The pads allow us to precisely set the elevation of the bridge’s superstructure.

In October 2020, during a regular inspection WSDOT bridge maintenance crews noted the bridge was moving on the bearing pads more than it should, so we did temporary repairs to keep the bridge stable while we planned the permanent fix.

There’s never a good time to reduce capacity on a major highway. However, scheduling this work allows people to plan ahead and consider alternate routes. It also helps us avoid the need for emergency repairs that require unscheduled closures. Thanks for your patience as we complete this vital work!