(a) There is established a system of state aid roads in each county consisting of the major collector and minor collector routes not on the state highway system feeding into local trade areas or into the state highway system and providing a program for the construction and improvement of state aid roads.
(b) There is set up for designation by cooperative action of the state and counties a state aid system of roads, as classified and defined in this subchapter, which system shall be designated by the several county judges of their respective counties with the consent and approval of the state aid engineer and the State Highway Commission to a total mileage not in excess of fifteen thousand (15,000) miles, including any municipal streets, and initially established at five thousand (5,000) miles, which five thousand (5,000) miles shall include all county roads on the federal-aid secondary road system. The system will periodically be expanded in one thousand-mile increments after the initial five thousand-mile system has been established.
(c) Nothing in this subchapter shall be construed to deprive or diminish the powers and duties of the county judge of any county in the exercise of his constitutional control over county roads.