I deal with a lot of traffic accidents in my practice, but I have yet to hear the term "unprotected light."
What seems to be common these days is for people to receive a citation for making a right turn at a red light. Although, they are legal in California, drivers are required to stop (like at a stop sign) before making their right turn.
Posted by www.accidentsinla.com to L.A. traffic sucks: Let's fix it! at 9:36 PM
I don't know how many technical terms there are to refer to this, but as far as I know, an "unprotected light," or perhaps more rightly, an "unprotected left," is a green light that allows you to turn (usually left) without an exclusive right-of-way. In other words, you can turn (usually left) but only after all oncoming traffic coming straight at you in the opposite direction to yours has passed. A "protected left turn light" would be a green light with an arrow giving you exclusive (e.i. protected) right-of-way to turn left. There are very few such "protected left turn lights" in L.A., and it is my contention that that fact contributes to the traffic problem as I explained in several posts.
The right terminology is only incidental. Call it what you will. It is the concept, and its effect on traffic, what matters...
Thanks for the comment.