All lanes of eastbound SR 518 will close overnight on Monday, Nov. 20, 2023 near Sea-Tac International Airport as a project to replace a damaged girder on the 24th Avenue South bridge wraps up.

Crews will install a drainage pipe along the bridge during Monday night’s closure.

Beginning at 9 p.m. Monday, Nov. 20, until 5 a.m. Tuesday, Nov. 21, all eastbound lanes of SR 518 will close between Des Moines Memorial Drive South and SR 99/International Boulevard. A signed detour will be available for eastbound SR 518 traffic, but delays can be expected.

This work will affect people going to Sea-Tac airport from SR 509 or the Burien area, while those going to the airport from the Interstate 5 corridor should see minimal delays related to construction.

Eastbound SR 518 detour

Eastbound SR 518 traffic will detour around the closure using southbound Des Moines Memorial Drive South, eastbound South 156th Way, eastbound South 154th Street and southbound SR 99/International Boulevard to the eastbound SR 518 on-ramp. People leaving on flights or meeting someone at the airport should plan for extra travel time.

Bridge girder replacement

The 24th Avenue South bridge was struck in 2020 by an eastbound over-height vehicle, severely damaging one of the bridge girders. In August, Washington State Department of Transportation contractor crews removed the damaged girder and lifted a new one into place. Since then, they have rebuilt the bridge deck over and reopened the bridge Nov. 1.


Below are videos courtesy WSDOT showing the demolition and replacement on the bridge:

The drainage pipe installation is the last major construction that is part of the project.

Real-time travel information is available vis the WSDOT mobile app, the WSDOT Travel Center Map or by signing up for WSDOT’s email updates.