Maybe you've seen one of these new traffic signals during your commute around Central Florida. The "flashing yellow arrow" or FYA, is a new feature being added tos ignals with protected-permissive left turn signals. Protected-permissive signals are those that stop oncoming traffic to allow left turning drivers to turn safely, before transitioning to a phase where drivers can still turn left, but must yield to oncoming traffic, first.
The flashing yellow arrow eliminates some of teh guesswork for left-turning drivers. With these signals in place, drivers still receive the solid green arrow when oncoming traffic is stopped and they are permitted to make their turn. However, the signal will transition to red (or a red arrow) as oncoming traffic is released, reminding the left turn drivers that they know longer have exclusive right of way and are not protected from oncoming vehicles.
With the previous signal design, drivers were often confused when the left turn arrow transitioned to a green ball; failing to understand that, even on green, they must yield. Yellow, universal for "yield or prepare to stop," helps to eliminate that confusion. Like any new traffic feature, there is a learning curve assiciated with these new signal configurations, but the FYA has proven to reduce the number of angle crashes at intersections. Angle crashes (also known as T-bone crashes) are the most dangerous and often result in significant bodily injury or death.