SEATAC – Construction starts Monday, Dec. 2, on an $8.3 million project that will repave two miles of State Route 99 and improve pedestrian safety at intersections in SeaTac and Des Moines.
Contractor crews working for the Washington State Department of Transportation will remove existing asphalt and resurface all lanes on SR 99/Pacific Highway between South 200th Street in SeaTac and SR 516 in Des Moines. Crews also will upgrade curb ramps at SR 99 intersections to Americans with Disabilities Act standards.
“Construction will primarily occur at night for the duration of this project,” said WSDOT Project Engineer Thomas La Bolle. “However, there will be some intermittent weekend-long lane reductions and local road closures for curb ramp installation.”
Contractor crews will spend the winter months installing dozens of new curb ramps at SR 99 intersections. Paving will start in spring 2025 when dry weather returns.
Closure details
Starting Dec. 2, single-lane closures on SR 99 will occur overnight Monday through Friday from 9 p.m. to 5 a.m. the following day for curb ramp replacement. Some weekend work will occur from 9 p.m. Friday night until 5 a.m. Monday.
In spring 2025, overnight SR 99 lane closures between South 200th Street in SeaTac and SR 516 in Des Moines will begin for asphalt removal and paving.
Signed detours, flaggers and law enforcement will guide people around and through work zones during this project.
What to expect during construction
Curb improvements will require nighttime saw cutting and concrete demolition. People who live near SR 99 can expect intermittent noise and vibration for several hours at each location during curb demolition.
Certain driveways will be inaccessible from SR 99 for up to 15 minutes during asphalt grinding and up to an hour during paving. This work will occur during overnight hours when traffic is lowest, and public notice will be provided in advance.
“This is a very busy corridor with businesses, homes and medical facilities,” La Bolle said. “We’ve designed this project to have the least possible impact on people who live, work and commute in this area.”