(a) Any person over eighteen (18) years of age who enters a school bus as defined in § 31-1-3 without prior authorization of the driver or a school official, and who refuses to disembark after being ordered to do so by the driver, shall be guilty of a misdemeanor.
(b) A school district may place a notice at the entrance of the school bus that warns against the unauthorized entry or refusal to disembark prohibited by this section.