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Project Overview

What is included in the project?

Key features of the SR 509, I-5 to 24th Avenue South – Expressway Project include:

Project timeline

The SR 509, I-5 to 24th Avenue South Expressway Project is the second construction contract (Stage 1b) of the SR 509 Completion Project. Construction will begin in late 2021 and end in 2025. WSDOT will complete the SR 509 Completion Project with a third construction contract (Stage 2) between 2024 and 2028. Stage 1a, which includes a new SR 99 bridge is currently under construction as part of Sound Transit’s Federal Way Link Extension light rail project.

A timeline displaying phases of work for the SR 509 completion project
The contractor is finalizing design and will start construction this year (2021). Major construction will start in 2022 and take about four years to complete.