Nearly 3,000 feet of new concrete barrier is set to be installed on northbound I-5 and the off-ramp to South 200th Street in SeaTac through April 14, 2023, requiring nightly ramp and lane closures.

To place the barriers, construction crews working for the Washington State Department of Transportation will close the northbound I-5 off-ramp to South 200th Street/Military Road South and up to three lanes on northbound I-5.

Ramp closure information

  • 7 p.m. Wednesday, April 5 to 4:30 a.m. Friday, April 7 – The northbound I-5 off-ramp to South 200th Street/Military Road South will close nightly.
  • 7 p.m. Monday, April 10 to 4:30 a.m. Friday, April 14 – The northbound I-5 off-ramp to South 200th Street/Military Road South will close nightly.
  • Drivers will follow a signed detour and should plan for additional travel time.

Lane closure information

  • 7 p.m. Monday, April 3 to 4:30 a.m. Friday, April 7 – Up to three right lanes of northbound I-5 will close nightly between South 221st Street and South 204th Street.
  • 7 p.m. Monday, April 10 to 4:30 a.m. Friday, April 14 – Up to three right lanes of northbound I-5 will close nightly between South 221st Street and South 204th Street./li>
  • The HOV lane and one left general purpose lane will remain open to all vehicles for travel.
  • Drivers should plan for additional travel time.

This work is part of the SR 509 Completion Project.