(a) If the commissioners court of a county determines that the general welfare will be promoted, the court may:
(1) establish by order building or set-back lines on the public roads, including major highways and roads, in the county; and
(2) prohibit the location of a new building within those building or set-back lines.
(b) A building or set-back line established under this subchapter may not extend:
(1) more than 25 feet from the edge of the right-of-way on all public roads other than major highways and roads; or
(2) more than 50 feet from the edge of the right-of-way of major highways and roads.
(c) The commissioners court may designate the public roads that are major highways and roads.