The Seattle Department of Transportation has begun early design work on a project to upgrade traffic signals along NW 80th St and NW 85th St.
The project covers both streets between 15th Ave NW and Wallingford Ave N. According to SDOT, the existing traffic signals are more than 20 years old and no longer meet current needs.
Planned improvements include modernizing signal timing, adding sensors to detect traffic, and connecting signals to SDOT’s Transportation Operations Center. SDOT says the connection will allow staff to monitor traffic and adjust signal timing in real time.
The upgrades are intended to better match signal timing with current traffic demand, reduce long waits at red lights, and improve reliability for buses and freight. The project will also include updates to some sidewalks, curb ramps, and crossings.
SDOT says the construction needs will vary by intersection. Some signals can be upgraded using existing equipment and overhead wires, while other locations will require trenching to install new equipment.
Potential construction impacts include pedestrian detours, temporary driveway impacts, parking restrictions, and lane closures. SDOT says more information about specific impacts will be available after the design process is complete and construction gets closer.
Final design could be completed as early as December 2026, with construction potentially beginning in mid-2027.
The signal work is another transportation upgrade affecting the Route 40 corridor. SDOT has also been completing improvements aimed at improving transit speed and reliability along Route 40 through Ballard and Fremont.
SDOT plans to continue outreach to neighbors and businesses during the design process through in-person outreach, email, and website updates.
Photo: Google Image Capture, 15th Ave NW and NW 85th St