Neb. Rev. Stat. §§ 39-1315.01
No road or highway shall be removed from the state highway system until a minimum of three years after such road or highway has been improved with a surface of concrete, asphalt, or material of similar quality, covering at least two traffic lanes, and then only after a determination that traffic along such road or highway is insufficient to justify retention of it as part of the state highway system. The provisions of this section shall not be construed to apply to (1) the relocation of a road or highway pursuant to subsection (2) of section 39-1309, (2) temporary detours or detours designated pursuant to section 39-1309.01, or (3) roads which are removed from the state highway system and added to a county road system or municipal street system pursuant to a contract or agreement between the department and the affected county or municipality. Such a contract or agreement shall not be canceled or amended unless agreed to by all parties to such contract or agreement.
Neb. Rev. Stat. §§ 39-1315.01