California Code, Vehicle Code - VEH § 22406.1

(a) A person who operates a commercial motor vehicle, as defined in subdivision (b) of Section 15210, upon a highway at a speed exceeding a posted speed limit established under this code by 15 miles per hour or more, is guilty of a misdemeanor.

(b) A person who holds a commercial driver's license, as defined in subdivision (a) of Section 15210, and operates a noncommerical  1 motor vehicle upon a highway at a speed exceeding a posted speed limit established under this code by 15 miles per hour or more, is guilty of an infraction.

(c) A violation of either subdivision (a) or (b) is a “serious traffic violation,” as defined in subdivision (p) of Section 15210, and is subject to the sanctions provided under Section 15306 or 15308, in addition to any other penalty provided by law.

(d) This section shall become operative on September 20, 2005.