Vashon Highway closure set for March 8 to April 9

The King County Road Services Division will be making repairs to the drainage system underneath Vashon Highway Southwest, and is scheduled to close a section of the road for five weeks starting Monday, March 8.

The project area is located between 115th Avenue Southwest and Southwest 242nd Street. The full closure is necessary because the county will be installing eight new culverts underneath the roadway to improve drainage and reduce local flooding. This requires digging deep trenches across the roadway. If possible, crews will place plates over the openings on the road and leave it passable for motorists in the evenings.

The culverts being replaced were originally installed 60 years ago and are failing, causing water to pond on the highway in that location. That creates driving hazards, particularly in the winter when ice forms. The poor drainage also erodes the shoulders that support the roadway.

During the closure, motorists can detour via Southwest 228th Street, 107th Avenue Southwest, Southwest 232nd Street, and Wax Orchard Road Southwest.