KNOX COUNTY, Tenn. — Whether you're driving to work or dropping off your kids off at school, it's likely you'll spend some time waiting and waiting at a red light.

10News viewer Nancy Ballard asked us to check in on a certain intersection in Knox County: Pellissippi Parkway and Hardin Valley. 

  • Ballard wrote, "I think the timing of the light changes is way off. I typically sit through three light changes. I have to allow a lot of extra time for a 15-minute drive to work."

Knox County engineers monitor 85 signals compared to more than 400 Knoxville. According to Knox County Engineer John Sexton, every intersection is uniquely timed.

"We set timing plans for a given corridor. Most of the time, the volumes of traffic and the direction of traffic changes," said Sexton. "The one we get the most calls on, the most congestion that we see is on Hardin Valley Road and Pellissippi Parkway."

Regulating the flow of traffic requires engineers to learn how the intersection functions and who uses it during peak traffic times.

Traffic is growing in the area. According to a traffic count in 2015, about 42,000 vehicles pass through the interchange. That's a 1-percent increase from 2009.

"We now have three county schools, Pellissippi State Community College, plus the commuter traffic,” said Sexton.

After counting the number of cars that use the intersection, engineers must determine the cycle length. That's how much time it takes to go from green to yellow to red. Typical lengths range from one minute to three minutes.

In Knox County, engineers adjust traffic signals every five to seven years. If you think an intersection needs a little adjusting, contact your city or county engineers to take a look at it.

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