Vehicle Code § 22100.5
CHAPTER 6. Turning and Stopping and Turning Signals
No driver shall make a U-turn at an intersection controlled by official traffic signals except as provided in Section 21451, and then only from the far lefthand lane that is lawfully available to traffic moving in the direction of travel from which the turn is commenced. No driver shall make a U-turn at an intersection controlled by official traffic control devices except from the far lefthand lane that is lawfully available to traffic moving in the direction of travel from which the turn is commenced.