The department shall maintain the highways forming the state highway system, together with the other facilities of the department to the extent that the revenues of the department will permit. The selection of the highways, facilities, or parts thereof to be maintained and the order of that selection shall be made by the secretary upon the recommendation of the chief engineer and may be changed from time to time as the case demands. In this selection, these officials shall be guided by volume and character of traffic and the convenience, safety, and necessity of the traveling public.
La. Roads, Bridges and Ferries § 48:259