Drivers across San Tan Valley, and all of Pinal County will soon notice a change at intersections: the addition of flashing yellow arrows for left turns. It's not just a cosmetic upgrade — it's a safety improvement that could reduce confusion and prevent crashes.

Thanks to a partnership between Pinal County Public Works and the Arizona Department of Transportation (ADOT), several traffic signals are being upgraded to include this newer signal pattern. The first phase of the project is underway along a key corridor, with five intersections already slated for updates. Over time, most — if not all — signalized intersections in the county will be retrofitted or constructed with this safer configuration.

Under the previous setup, left turns were managed with a green arrow for protected turns and a solid green light (also called a "green ball") to indicate that drivers could turn left when it was safe — known as a "permissive" turn. But the green ball has proven confusing for many drivers. While it means go when driving straight, it doesn't always mean the same when turning left, leading to hesitation or misjudgment.

That's where the flashing yellow arrow comes in. Studies from the Federal Highway Administration show that replacing the green ball with a flashing yellow arrow helps clarify the rules of the road: proceed with caution, and yield to oncoming traffic. According to national research, this simple change has the potential to reduce left-turn crashes by as much as 20%.

The new arrows are also more efficient. By more clearly communicating when drivers can turn left, the flashing yellow signal helps get a few more cars through the intersection during each cycle, helping traffic flow more smoothly.

"We're doing this for two main reasons: safety and consistency," explained Pinal County officials. "The flashing yellow arrows are easier to understand, and other agencies in our region are making the same upgrade. That means no matter where you drive, you'll start to see the same left-turn signals — and that consistency makes a difference."

As Pinal County continues to grow and add new infrastructure, these upgraded signals will be part of all future traffic signal projects.