King County begins work on intelligent-road projects in Juanita

King County begins construction this month on two more Intelligent Transportation System (ITS) projects, and this set will speed up traffic flow in busy corridors north of Kirkland.

The county’s latest ITS projects focus on two streets in the Juanita area. Overall, the work includes interconnecting traffic signals at 10 intersections on 100th Avenue Northeast and Juanita-Woodinville Way Northeast/Northeast 160th Street. These projects will also connect to the existing ITS system on Northeast 124th Street in Totem Lake to provide a network of traffic coordination in unincorporated areas of King County on either side of Interstate 405 north of Kirkland.

“Over the past decade, we’ve seen a huge decrease in funding for new road construction,” said Linda Dougherty, director of the King County Road Services Division. “That’s why technology is playing an increasingly important role in our ability to unlock gridlock and keep people and goods moving.”

The county already has ITS networks on: the Trans Valley corridor between Renton and Tukwila; along Northeast 124th Street in Totem Lake; and Avondale Way/Novelty Hill Road east of Redmond. All of the ITS projects in King County use high-speed data and video transmission to connect traffic control centers to the individual intersections in the corridor. The high-speed transmission takes place along fiber optic cable, which provides high bandwidth at a low relative cost.

The $2.23 million package of projects in Juanita includes the installation of fiber optic links and real-time traffic cameras that feed data to the Road Division’s traffic control center, allowing engineers to synchronize traffic signals and remotely operate those signals when necessary to relieve congestion. It also lets the county share traffic data with other agencies to keep traffic flowing across jurisdictional borders.

For the Juanita projects, the Road Services Division is working with the city of Kirkland to run fiber optic cable through city right-of-way. The fiber will connect the 100th Avenue and Juanita-Woodinville corridors to the existing transportation communication hub in Totem Lake. That will provide King County with a communication pathway from the Juanita corridors to its control center in Seattle. And by using existing conduit, the county is saving more than $800,000 on the new projects.

There is also coordination with the city of Woodinville to upgrade the traffic signal at 124th Avenue Northeast and Northeast 160th Street.
 
Dougherty said that signal synchronization and other ITS elements can achieve significant reductions in travel time and fuel consumption, which also improves air quality, traffic safety, and eases stress for motorists. The Roads Division’s before-and-after studies on existing ITS corridors shows reduced travel times between 20 percent and 45 percent in the peak direction of travel.

Construction is just beginning on the Juanita projects, and will last through June. During the installation, traffic disruptions should be limited to lane and shoulder closures between 9 a.m. and 3 p.m. on weekdays. As the ten traffic signals are individually upgraded, there may be times when police will be directing traffic through the intersections.

The Road Division has several other new ITS projects in the pipeline. They include:
• Finalizing the design for the South 277th Street project between Kent and Auburn. Construction should begin in the fall;
• Starting design on Avondale Road Phase I, with a projected construction start of winter 2009-2010;
• Beginning design for a 2010 project for 16th Avenue Southwest in White Center;
• Upgrading signal equipment and adding cameras on Issaquah-Hobart Road at the May Valley and Cedar Grove Road intersections, along with a new variable message sign south of Cedar Grove Road; and
• Installing seven new cameras at various locations in unincorporated King County. These cameras will be used by King County signal operations engineers, roads maintenance, and linked to the MyCommute website for public use.