(a) The department shall erect a "Welcome to Texas" sign to designate the state boundary on an interstate, United States, or state highway entering the state.
(b) A "Welcome to Texas" sign erected by the department must include the following elements:
(1) a depiction of the state flag; and
(2) the phrase "Drive Friendly - The Texas Way."
(c) A "Welcome to Texas" sign may also include the phrase "Welcome to Texas - Proud Home of Presidents Lyndon B. Johnson, George H.W. Bush, and George W. Bush."
(d) Notwithstanding Subsection (c) above, if the president of the United States is a resident of Texas, a "Welcome to Texas" sign erected by the department shall include the phrase "Welcome to Texas - Proud Home of President [insert name of the president of the United States]."