Boeing Access Road over Airport Way Seismic Retrofit

Project Overview

Boeing Access Road is a principal arterial connecting I-5 and East Marginal Way South. It is considered regionally significant and is included on the National Highway System for access to the Boeing Company and the King County Airport at Boeing Field. The Boeing Access Road over Airport Way Bridge is the only remaining structure on the Boeing Access Road corridor that has not been seismically upgraded. This improvement would allow the entire corridor to be seismically resistant during a seismic event.

The seismic retrofit to the bridge consists of an upgrade to the east and west approach slabs on Boeing Access Road. During the construction of the approach slabs, Boeing Access Road will be reduced from two (2) lanes in each direction to one (1) lane in each direction. Daily commuters are asked to be aware of the reduction and use alternate routes during this portion of the construction project.

A majority of the construction work will be located under the bridge on Airport Way. Construction crews will be placing steel jackets around the concrete columns and will be adding  strength members to the concrete girders. Traffic using Airport Way will be adjusted around the construction zone to allow construction crews access to the bridge columns without reducing traffic lanes.

Please note that traffic volumes could be higher in this area due to the closure of the West Seattle Bridge.


Project Status Update – 3/08/21

Construction crews will be completing the final weather dependent task on Monday, March 8, 2021 and will be removing the traffic control on Boeing Access Road. Traffic control will also be removed on Tukwila International Blvd and on Marginal Way, opening all eastbound and westbound lanes through the project site.

Please note, the contractor can/will be performing intermittent temporary flagging operations and lane restrictions to provide street cleaning and lane markings during optimal weather windows.

Work continues on the underside of the bridge with minor lane shifting on Airport Way as crews install bridge strengthening steel jackets on the concrete bridge columns.



Contact Information

For specific  questions or concerns you may contact Adam Cox, Bridge Project Manager at (206) 431- 2446 or via email at

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