News from King County Department of Transportation
Release date:  April 3, 2007

Vashon-Maury Island road/seawall preservation eyed for major King County review

Two major Vashon-Maury Island travel corridors, and the seawalls that protect them, will be the focus of a major study to determine critical investments that will be needed in the coming years to preserve safety and mobility on the island. The proposed work program and timeline for determining key infrastructure improvements has been submitted to the King County Council for review and approval.

“This work plan describes how the county’s transportation department will methodically and comprehensively examine the types of important investments needed in the coming years to preserve Vashon Highway and Dockton Road Southwest,” said King County Executive Ron Sims. “As I said when proposing this year’s county budget, the preservation of our transportation system is a fundamental responsibility we must take seriously. This work program demonstrates our commitment to carrying out that responsibility by preserving the most vital transportation routes on Vashon/Maury Island.”

The county’s transportation department is proposing to begin a full analysis of project alternatives for preserving and improving a three-quarter mile stretch of Dockton Road Southwest and adjacent seawall just north of Quartermaster Drive. The county will also examine a three-quarter mile stretch of Vashon Highway and seawall just south of Southwest Burton Drive.

The seawalls play a key role in protecting both roads. However, long sections of deteriorating wall are more than 80 years old and have failed in many places due to rotting timbers, deteriorating rockery material, ongoing wave action and damaging storm surges. It is no longer possible to make spot repairs to insure the long-term safety of the roadways.

The roadways themselves are also in need of rehabilitation. Dockton Road was constructed in 1916 and carries about 3,500 vehicles each day. The seawall supporting Vashon Highway was constructed in 1926. Vashon Highway serves as a lifeline route connecting island neighborhoods and ferry terminals. More than 10,000 residents live on the island.

Both projects are also ranked at the top of the King County Road Services Division's list of most vulnerable road sections and are considered key to the island’s mobility.

Road engineers will begin analyzing project alternatives for Dockton Road Southwest, including potential environmental, traffic and community impacts, as well as alternative roadway alignments  following council approval of the work program. That analysis – scheduled to begin in 2008 – will be followed by a similar effort devoted to assessing alternatives for improving Vashon Highway.

Both efforts will include citizen involvement and will likely require a separate state or federal environmental review before a preferred alternative is selected. Actual project construction is unlikely to occur for several more years.