Find Posts By Topic

Now open: The new old Airport Way South Bridge

The old timber  approaches to the bridge were replaced with stabilized earth walls.


Built in 1928, the Airport Way South Bridge over the Argo Railroad yard has a new lease on life after a 14-month closure.  During the lengthy closure the viaduct was all but torn down and rebuilt.  An important link in the transportation network for businesses, freight operations, the Port of Seattle, commuters, cyclists and residents of the surrounding community, the bridge endured heavy traffic (over 13,000 vehicles daily) and increased stress over time.

The major makeover of the 84-year-old bridge included making ground improvements to address poor soil conditions at the viaduct approaches; replacing the original north and south timber-framed approaches with a stabilized earth wall structure; removing the precast decking of the viaduct and restoring steel structure of the main span while adding seismic improvements ; installing floor beams and girder strengtheners;  rehabilitating the existing concrete columns; enhancing the drainage system; and finally, pouring a new concrete driving surface on the main span and installing new guardrails.  All that remains to be done is painting the lane markings on the bridge which is on hold until the weather is more favorable.

Good for decades to come – this view of the bridge shows the beautifully rehabilitated main span steel structure and concrete columns,


The project, paid for by the Bridging the Gap voter-approved transportation levy, improves safety by creating a sturdier, more durable structure to serve current and future traffic conditions. The rehabilitated bridge keeps freight moving with a stronger structure that improves the load-carrying capacity of this vital structure. The more durable concrete deck and approaches will significantly reduce maintenance requirements and the frequency of major repairs and associated traffic disruptions. Completion of the project means one less bridge on the City’s extensive transportation maintenance backlog.

SDOT is proud of the completed project and commends all involved with this significant work. The viaduct construction was no easy task – it was complicated by the fact that it had to be carried out over an active railroad yard; had to maintain the existing main span super structure; and had to be done around a limited access site on a foundation containing liquefiable (weak) soils. Timing of work involved a great deal of coordination. Add to that, the crews had to constantly monitor and minimize the amount of movement to the existing underground utilities; including the high pressure gas main which runs right next to the viaduct and is a crucial north-south feed serving the region.

To see photos of the various phases of work on the bridge, please visit the project website.

You may view the official Bridge Re-opening Ribbon Cutting Ceremony at: