If the commissioners court of a county determines that the improvement of a road in a subdivision or of an access road to a subdivision is necessary for the public health, safety, or welfare of the residents of the county, the commissioners court may propose to:
(1) improve the road to comply with county standards for roads; and
(2) assess all or part of the costs of the improvement pro rata against the record owners of the real property of the subdivision or a defined part of the subdivision.