• Contract

SR 509, 24th Avenue South to South 188th Street – New Expressway

Contract summary

WSDOT will build the remaining two miles of new SR 509 Expressway, reconfigure SR 509 interchanges at South 188th and South 160th Streets and add a southbound auxiliary lane on I-5 between SR 516 and South 272nd Street.

Public Works
Publication Date
Contract status
Contract ID
King County
Submittal due date and time
Estimated value
$400,000,000 - $500,000,000
Funding source
A federally funded contract with a 15% disadvantaged business enterprise condition of award goal for the design portion and a 22% goal for the construction portion.
Ali Amiri
Project Manager