A person may not, without lawful authority, alter, injure, knock down, or remove or attempt to alter, injure, knock down, or remove:
(1) an official traffic-control device or railroad sign or signal;
(2) an inscription, shield, or insignia on an official traffic-control device or railroad sign or signal; or
(3) another part of an official traffic-control device or railroad sign or signal.
Official text of the Texas Transportation Code as published by the Texas Legislative Council.