FOR THOSE OF YOU SAYING THIS IS AN MUTCD VIOLATION: Oregon petitioned for and received an exemption to permit the use of this. That being said, the MUTCD is NOT some sort of traffic engineering gospel that must be followed to a T but rather, suggestions for a unified design. Some states use just the MUTCD, some use it with their own supplements (such is the case here) and others such as California and Texas, use their own manual, forgoing the federal one entirely.
The flashing yellow arrow signal is slowly making its way around the US but you may not know that Oregon came up with this variant long before the FYA itself was even federally approved. Medford would set up their left turn signals this way even back in the 90s and it's now tentatively approved for statewide use. It makes sense as it requires no additional sections or LED modules and the signal can be converted back to a protected-only left with nothing more than a quick reprogramming of the controller.
![](https://i.ytimg.com/vi/77d21xoHF6k/mqdefault.jpg)