(a) The commissioners court of a county may:
(1) make and enforce all necessary rules and orders for the construction and maintenance of public roads;
(2) hire the labor and purchase the machinery and equipment needed to construct and maintain public roads; and
(3) use any necessary material most convenient to build, repair, or maintain public roads, regardless of the location or extent of the material.
(b) The court may enter any necessary order for the use of inmates of the county jails to work on the county roads or to build bridges.