Link light rail construction across SR-518 continues; full nighttime highway closures coming this week

Sound Transit’s construction of a new light rail bridge across SR-518 just west of International Boulevard near Sea-Tac International Airport continues this week after a brief pause during the July 4 holidays.

• All westbound and one eastbound lane of SR518 will be closed Monday night just west of International Boulevard.
• Full nighttime closures of SR518 in both directions are scheduled for this Tuesday, Wednesday and Thursday just west of International Boulevard.
• Detour routes for all closures will be posted on the highway.

Lanes will begin closing progressively at 7 p.m. with the full closures occurring at 11 p.m. All lanes will reopen by 5 a.m.

Crews are employing a construction method and schedule that keeps the freeway open during the day, limiting lane closures and traffic impacts to nighttime hours. 

The construction utilizes pre-cast concrete segments in a balanced cantilever design, a method last used in the Puget Sound region last winter when Sound Transit built a light rail bridge crossing I-5 near Boeing Access Road. 

For the SR-518 bridge, two large bridge piers have been built, one on each side of the freeway just west of the existing International Boulevard overpass. Starting with the pier adjacent to westbound SR-518, giant cranes are hanging the pre-cast segments one at a time on alternating sides to keep the structure in balance. Steel tensioning cables running through the segments keep them in place as the structure extends in each direction. 

The schedule for this work is subject to change if necessary.  The latest schedule information is posted at projectupdates

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Sound Transit’s regional network of express buses, commuter rail, light rail and transit facilities connects communities in King, Pierce and Snohomish counties.