The South 216th Street bridge spanning Interstate 5 in SeaTac welcomes both directions of traffic starting today, June 5. This marks a significant step forward for the Washington State Department of Transportation's (WSDOT) State Route 509 Completion Project. In a release from WSDOT, it’s noted that construction teams are wrapping up the northern side of the newly expanded bridge. The southern side had been operational for westbound traffic since December 2023, funneling eastbound vehicles onto an alternative route to traverse the interstate.
Stretched over additional lanes being added to I-5, the new bridge extends 335 feet in contrast to the a 290 feet of its predecessor. These extra lanes are paving the way for the future connection of on- and off-ramps linking SR 509 expressway with I-5. Beyond its length, the bridge has been upgraded to better cater to those not behind the wheel. "The previous bridge’s sidewalks were too narrow for people who use wheelchairs and forced bicyclists merge with vehicle traffic to cross," Ward Anderson, the project engineer, told WSDOT. The new construction boasts dedicated bike lanes, sidewalks that are ADA-accessible, and a brand-new eastbound turn lane onto Military Road South.
Though motorists can start using the bridge, some construction work remains unfinished. According to WSDOT, this includes installing curbs and gutters, laying the final pavement, and adding permanent striping on both the bridge and the approach roads. These tasks will necessitate occasional single lane closures and a couple of full road closures to complete the paving and striping work.
The larger SR 509 Completion Project, when completed, will introduce an additional 3 miles of tolled highway connecting I-5 to South 188th Street, near the south end of Seattle-Tacoma International Airport. Currently, the stretch between I-5 and 24th Avenue South is slated to open in 2025, with the project’s entirety expected for completion by 2028. Further details can be found on WSDOT's website.
