(a) In a county that employs road commissioners under this subchapter, the commissioners court shall ensure that the county road and bridge fund is judiciously and equitably spent on the roads and bridges in the county. As nearly as the condition and necessity of the roads permit, the fund shall be spent in each county commissioner's precinct in proportion to the amount of money in the fund collected in the precinct.
(b) In a county that employs road commissioners under this subchapter, money used in building permanent roads must first be used on:
(1) first-class or second-class roads; and
(2) roads for which the right-of-way has been furnished free of cost to make as straight a road as is practicable and for which the residents have offered the greatest amount of labor, money, or other property.