This would most likely be in its own turn lane, as you don't want turning traffic that has to sometimes yield for oncoming to block others going straight. The lights give two different conditions, one where the driver has right-of-way (the arrow), and the other where it's up to the driver to determine conditions before proceeding.

In my area instead of this setup we now have two lights - one is a green arrow alone for right to turn, and the other is a yellow flashing arrow meaning to turn with caution only when it's clear. And while that may sound more obvious, when they were initially put up people had a lot of trouble with it. Just like when the first roundabouts started popping up. Now both are common and part of normal driving.