Lane striping on the newly repaved section of SR 99 between South 200th Street in SeaTac and SR 516 in Des Moines begins Saturday night, Aug. 16, and last for about three weeks.
Nightly lane closures on both directions of SR 99 along this 2-mile corridor will happen from 9 p.m. to 5 a.m. nightly Saturday nights through Friday mornings. This work requires dry weather and could be rescheduled if rain is forecast.
People traveling along this corridor at night should plan for overnight double lane closures and occasional full directional closures for striping. Signed detours will guide people around any directional closures.
Project overview
This project will rehabilitate nearly two miles of State Route 99 from the SR 516 intersection in Des Moines/Kent to South 200th Street in SeaTac. Crews will grind away existing asphalt and install new hot mix asphalt, giving the roadway a smoother surface and extending its lifespan. Pedestrian curb ramps will also be evaluated and updated as necessary to meet the Americans with Disabilities Act and current accessibility standards.
What to expect
Contractor crews have successfully upgraded more than 30 curb ramps along this two-mile section of SR 99 to modern ADA standards.
Paving begins June 7, 2025, and will last about two months, weather permitting. During construction, crews will grind the road surface and install a new course of hot mix asphalt. People can expect single- and double-lane closures along SR 99, and directional closures for intersection paving, during this project.
Driveway access along SR 99 will be limited for up to 30 minutes at a time during asphalt grinding, and up to two hours during paving. Both activities will occur overnight when traffic volumes are lowest. Advance notice will be given in these locations.
This project will pave and make ADA improvements in both directions of State Route 99 from SR 516 to South 200th Street.