(a) To promote the public safety, the commissioners court of a county with a population of more than 1.3 million by order may regulate the following in the unincorporated area of the county if they occur on a public highway or road, in the right-of-way of a public highway or road, or in a parking lot:
(1) the sale of items by a vendor of food or merchandise, including live animals;
(2) the erection, maintenance, or placement of a structure by a vendor of food or merchandise, including live animals; and
(3) the solicitation of money.
(b) The commissioners court of a county with a population of more than 870,000 that borders the United Mexican States by order may regulate the activities described by Subsection (a) in the manner described by that subsection, except that:
(1) the regulation of activities on or in the right-of-way of a public highway or road is limited to public highways and roads with a speed limit of 40 miles per hour or faster; and
(2) the county may not prohibit the sale of livestock.

(c) A county regulating vendors under Subsection (b) may require that a vendor be located not closer to the edge of the public highway or road than a distance that is equal to one-half the width of the right-of-way adjacent to the highway or road.