Benefits of a Flashing Yellow Arrow
A flashing yellow arrow for left turns at an intersection means that motorists should slow down and use caution when turning, and must yield the right-of-way to oncoming traffic as well as any pedestrians who may be crossing the intersection.
A flashing yellow arrow signal offers operational benefits that are not possible with the current 5-section (also known as “doghouse”) left turn signals. A signal’s left turn phase could operate as protected only with the green and solid yellow arrows during certain hours of the day and then as protected / permissive during other hours of the day, depending upon typical traffic flows.
The flashing yellow arrow may also be displayed before and / or after the protected green and solid yellow left turn arrows to improve traffic flow. The steady yellow arrow retains its standard meaning: The left-turn signal is about to change to a steady red arrow and drivers should prepare to stop or, if they have already entered the intersection, they should complete the left turn when oncoming traffic has cleared.
The Federal Highway Administration has adopted the flashing yellow arrow as a preferred practice for protected/permissive left-turn operations. The first new signal in Indiana was installed in late September or early October 2013 at U.S. 40 and Salisbury Road in Richmond, Indiana. The cost per intersection for this upgrade was approximately $900.
A National Cooperative Highway Research Program study demonstrated that drivers found flashing yellow left-turn arrows more understandable than traditional yield-on-green indications. The flashing yellow arrow will communicate to drivers that they must proceed with care and decide if there is a sufficient gap in oncoming traffic to make a left turn.
The flashing yellow left-turn arrow has been shown to be especially effective at intersections with high volumes of traffic and also provides traffic engineers with more options to handle variable traffic volumes. Motorists have more opportunities to make a left turn with a flashing yellow left-turn arrow than with traditional protected/permissive left-turn signals.