• Project

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

Project overview

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

Summer 2022 – spring 2023
Project status
$7.8 million

What to expect

People driving northbound on I-5 may see one lane closed nightly from 9 p.m. until 5 a.m. and as late as 9 a.m. on Sundays. At times, people driving southbound on I-5 to the southbound I-405 ramp may experience lane reductions nightly between 9 p.m. and 5 a.m. or as late as 9 a.m. on Sundays.

People driving on Northgate Way may experience one lane reduction between North 107th Street and Fifth Avenue Northeast nightly from 9 p.m. to 5 a.m. and opening as late as 9 a.m. on Sundays.

People driving on the Maple Road Bridge could experience one-way alternating traffic with flaggers stationed at each end nightly from 7 p.m. to 9 a.m.

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