• Project

I-5/Northgate Way & Maple Rd Bridges – Seismic Retrofit - Complete September 2023

Project overview

Through summer 2023, our contractor crews strengthened three bridges on Interstate 5 so they can better withstand a major earthquake. They wrapped steel “jackets” around the columns that support the bridges to hold the concrete together in an earthquake, reducing the chance of collapse. They also added concrete and reinforcing steel between the girders that support the bridge to keep them from moving in the event of an earthquake. The guardrail was replaced, as well.

Summer 2022 – summer 2023
Project status
$7.8 million

What to expect

Work on this project is complete.

Beginning in summer 2022, we strengthened overpasses at two locations - Northgate Way in Seattle and Maple Road in Lynnwood. This will help the overpasses to avoid collapsing in a major earthquake.