Getting better performance out of our traffic signals is a high priority, both for Public Works and for the Board of County Commissioners. The Traffic Signal Optimization Program allows the county to improve traffic flow and make rapid signal adjustments in response to accidents, construction or everyday congestion.

Technology

For decades, most traffic signals were governed by a programmed cycle dictating how much time is allotted to red, green and, for some signals, left-turn movements. Magnetic detectors embedded in the pavement also allowed vehicles to “trigger” a cycle change and provided some ability to hold green lights for vehicles.

With new technology, the county is able to enhance those capabilities by adding video and radar detection. Modern signals can use this technology to detect oncoming vehicles and adjust signal timing more efficiently and safely for traffic flow.

The county’s goal is to manage traffic signals as an integrated network, not a collection of individual controllers. Someday, motorists could travel the length of the Padden Parkway-78th Street corridor and get a green light at every county-controlled intersection.

Projects

The county already has completed an upgrade of traffic signals on Northeast 134th-139th Street in Salmon Creek. The project involved 17 different intersections, including NE 20th Avenue/Highway 99 and NE 129th Street/Highway 99 intersections.

That project will be tied into additional signal, road and freeway work that will be done with the Salmon Creek Interchange Project. The completed work also will allow the county to adjust signal operations and better manage traffic during construction, instead of simply defaulting to a programmed cycle for signal operations.

Other recently completed signal upgrades include:

• NE 99th Street at 124th, 130th and 137th avenues.
• NE Ward Road-172nd Avenue.
• NE 78th Street-Andresen Road.
• NE Hazel Dell Avenue at 81st and 82nd street.

During the first nine months of 2010, Public Works installed or upgraded 27 new signals, more than the previous five years combined. Most of the work has been paid for using federal grants.

Upcoming work

In coming years, Public Works intends to optimize signal coordination in other corridors, including NE Andresen Road/Padden Parkway, NE 88th Street (Highway 99 to St. Johns Road), NE 99th Street (west and east of Interstate 5) and Highway 99.

Report problems

If you see a malfunctioning traffic signal, please call our Customer Service lines at (360) 397-2446 or submit an online road maintenance request.