Flashing Yellow Lights
​You may start to notice a new type of left-turn signal on Kentucky’s roads. The new signal displays are known as Flashing Yellow Arrows and potentially offer a safer and more efficient way to establish right-of-way for left-turning vehicles at signalized intersections.

What the New Displays Look Like

The Flashing Yellow Arrow signal display is a four-section signal head that incorporates a green left-turn arrow display for protected left-turn movements and a flashing yellow arrow display for permitted left-turn movements. It will replace the more traditional five-section head, which incorporates a left-turn arrow display for protected left-turn movements and green ball display for permitted left-turn movements.

When These Displays be Installed

The Transportation Cabinet plans to start installing these displays in late 2009 and early 2010. Metro Louisville installed Kentuckys the first Flashing Yellow Arrow Display in November of 2009. Where Will These Displays Be Installed? At the present time, Transportation Cabinet engineers have identified approximately 45 state-maintained displays where this display will initially be installed. Metro Louisville has installed the Flashing Yellow Arrow Display at one intersection in Jefferson County. In addition, the Lexington Fayette Urban County Government plans to use this display at selected traffic signals along the Man O’ War Boulevard corridor. Expanded use of this display will depend on the effectiveness of this initial effort.

Why Use These Displays?

For many years, some engineers have had concerns that drivers turning left on a permissive circular green signal indication might inadvertently mistake that indication as implying the left turn has the right of way over opposing traffic. As a result, federal research was authorized to study alternative signal displays. This research suggests that the Flashing Yellow Arrow display offers the following advantages:

  1. Provides increased versatility in traffic signal phasing which can result in reduced delays at signalized intersections.
  2. Provides a separate signal display for left-turn lanes as opposed to a shared display for left and through movements.
  3. Has a high level of driver comprehension.

How the New Displays Operate

The displays associated with flashing yellow displays and driver expectations are as follows:

Flashing Yellow Operation

Flashing Yellow Arrow Animation

Additional Resources

  1. Flashing Yellow Arrow graphic
Contact Information Contact Info
Division of Traffic Operations
Kentucky Transportation Cabinet
200 Mero Street
Frankfort, KY 40622
Phone: (502) 564-3020
Fax: (502) 564-7759
Email: jeff.wolfe@ky.gov
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Jeff Wolfe, PE, Director