Vehicle Code – VC 15308

(a) A driver shall not operate a commercial motor vehicle for a period of 120 days if the person is convicted of a serious traffic violation involving a commercial or noncommercial motor vehicle and the offense occurred within three years of two or more separate offenses of serious traffic violations that resulted in convictions.

(b) Notwithstanding Section 13366.5 , the time period under subdivision (a) shall not commence until all existing suspensions or revocations of the commercial driving privilege have ended.