From 8 p.m. to 5 a.m. nightly Monday, April 6, through Friday morning, April 10, the left lane of northbound SR 99 will close between S 216th Street and S 200th Street in SeaTac for lane striping and curb upgrades.
At least one northbound SR 99 will remain open nightly through this area.
Project overview
This project has rehabilitated nearly two miles of State Route 99 from the SR 516 intersection in Des Moines/Kent to South 200th Street in SeaTac. Crews ground away existing asphalt and installed a fresh layer of hot mix asphalt, giving the roadway a smoother surface and extending its lifespan. More than 30 pedestrian curb ramps also were updated 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 is complete along both directions of SR 99 between South 200th Street and SR 516, and lane striping is nearly finished along this two-mile corridor. Intermittent SR 99 lane closures likely will continue through April 2026 for landscaping, lane striping and final "punch list" items to complete the project.
This project will pave and make ADA sidewalk ramp improvements in both directions of State Route 99 from SR 516 to South 200th Street.
This stretch of SR 99 was first opened in 1927 and today is a popular route to and from the Seattle-Tacoma International Airport with about 30,000 travelers using the roadway daily. The road was last paved in 2006.