I-5/Mounts Rd to Steilacoom-DuPont Rd – Corridor Improvements

Client

Washington State Department of Transportation

Completion Date

2026

Designer

Jacobs Engineering Group

Location

DuPont, Washington

Delivery Method

Design-Build

Division

Northwest

Contract Value

$188 million
rendering of new diverging diamond interchange at I-5 and Steilacoom-DuPont Road

This project addresses chronic traffic congestion and improves mobility around Joint Base Lewis McChord. Work included a new modified split diverging diamond interchange at Steilacoom-DuPont Rd and the widening of I-5 to include high-occupancy vehicle (HOV) lanes and auxiliary lanes in both directions.