(a) When the commissioners court of a county has established a county road and (i) the laying out of the road has been established by a jury of view, (ii) the county road has been in continuous use for more than 30 years, and (iii) public funds have been expended for the upkeep and maintenance of the road for at least 10 of the last 20 years, the commissioners court of a county may declare that the road shall continue to be used as a public road.
(b) When the commissioners court of a county determines after declaring such road a public road that it is in more than one county, the commissioners courts of the counties in which the road is located may allocate by mutual agreement the costs of maintenance of the road upon a finding by the commissioners courts of the counties that the continued maintenance of the road as a public road would be of benefit to the counties.

(c) It is hereby found by the legislature that all orders enacted by the commissioners court of a county in establishing such county roads and orders authorizing the expenditure of public funds for the construction and maintenance of public roads were enacted for a public purpose and all such orders are validated in all respects.