What it takes to keep traffic flowing in Lynnwood

LYNNWOOD — You’re stuck in traffic. It’s 5 p.m. and you’re tired of waiting for that left-turn signal to turn green.

Employees who oversee Lynn­wood’s Intelligent Transportation System say they understand the frustration.

Their job is to monitor traffic and make sure streets run as smoothly as possible.

“We’re committed to giving a better driving experience for everyone,” said Paul Coffelt, project manager.

When the traffic management folks do their jobs, drivers shouldn’t notice, public works director Bill Franz said.

Working from a cramped collection of cubicles inside City Hall, these techno wizards operate what at least one outside expert considers to be one of the best traffic management centers around.

They oversee the computers that synchronize street lights and walk signals and give police, firefighters and buses green-light specials when needed.

“The whole system is coordinated to give the best possible outcomes to traffic flow,” deputy public works director Jeff Elekes said.

To monitor the city’s 67 intersections involves high-tech coordination. Each intersection is equipped with a video system that provides immediate feedback on the number and frequency of vehicles at an intersection. That information feeds into the computerized controller, which can make automatic adjustments.

All that data is useful, Coffelt said, because it helps engineers make decisions on how to redirect traffic or change the signal timing.

Last March, for example, feedback from traffic cameras at Highway 99 and 174th Street SW allowed traffic monitors to reroute vehicles following an accident in the highway’s northbound lanes.

And a July mishap involving the collapse of a Snohomish County Public Utility District pole along 196th Street SW also led to quick alterations in signals.

“Those events show the real power of the system,” Franz said. “In the old days, we’d have to send technicians out to the (controller) boxes.”

Now, Coffelt added, “a couple people can do all the traffic mitigation.”

And they can do it from the comfort of their own traffic management center at City Hall.

One man who’s been impressed with Lynnwood’s traffic monitoring operation is Yin Hai Wang, associate professor of civil and environmental engineering at the University of Washington.

He oversees the college of engineering’s Smart Transportation Applications and Research Laboratory, which goes by the acronym SMART. There, doctoral students work to solve traffic problems with cutting-edge technology.

“I would say the city of Lynn­wood’s traffic sensor configuration is the best in the United States,” Wang said.

Lynnwood traffic data has been analyzed by his lab.

“Since we founded this lab in 2003, we’ve gotten very strong support from the city of Lynn­wood,” he said. “And we’ve found a starting point to integrate our research.”

One reason Lynnwood’s system is ahead of the pack, he said, is its use of video detection. Most cities still use copper wire loops embedded in the pavement to track vehicle traffic. While that approach works well, it has limitations.

Video detection gives a broader, more detailed overview of the intersection’s traffic patterns, Wang said.

“For example, you can always manually verify if this data is correct,” he said.

Wire loop systems, unlike video systems, also have to be dug up during road construction work.

“We really do want the feedback from people if they do have an isolated or ongoing experience, we’d like to hear from them,” Coffelt said.

“We’ll actually do research; we’ll look at history and start capturing the detection data history. We follow through with every call that comes in.”