(a) If a road in a subdivision or an access road to a subdivision is located in a municipality, the county may improve the road only if the governing body of the municipality and the commissioners court:
(1) agree that the county may improve the road; and
(2) in the agreement indicate whether the improved road will become a county road or a municipal road.
(b) Before a county may improve a road located in a municipality under this section:
(1) the county must meet the other requirements of this subchapter; and
(2) the commissioners court of the county must find that the improvement of the road serves a county purpose.
(c) Section 253.011 does not apply to a road improved under this section.