• Project

I-5 - SR 161 - SR 18 Triangle Interchange Vicinity - Improvements

Project overview

Improved safety, mobility, and less congestion are the hallmarks of the planned improvements at the I-5/SR 18/SR 161 interchange in Federal Way. This project will build on previous improvements to add a new southbound exit to South 356th Street, rebuild the existing exit to SR 18, and realign the SR 161 intersection with Milton Road South/20th Avenue South. These improvements will be built in phases.

Project status
$85 Million

What to expect

Design, engineering, and environmental analysis work will continue through 2023. Construction is tentatively scheduled to begin in 2023. More information about how construction work will affect highway users will be provided closer to the start of construction.

This map shows the locations of improvements planned for the I-5/SR 161/SR 18 interchange in Federal Way, WA.