(a) The commission may purchase or acquire by eminent domain a commercial sign that is lawfully in existence on a highway in the interstate or primary system.
(b) If an acquisition is by eminent domain, the commission shall pay just compensation to:
(1) the owner for the right, title, leasehold, and interest in the commercial sign; and
(2) the owner or, if appropriate, the lessee of the real property on which the commercial sign is located for the right to erect and maintain the sign.