Neb. Rev. Stat. § 39-1346

When (1) any portion of the state highway system is impassable or dangerous to travel, (2) it shall be deemed necessary, because of construction or maintenance work or for other reasons, to suspend all or part of the travel thereon, or (3) it is impracticable to maintain any portion of the state highway system as laid out, the department may route travel over a detour around such portion of the state highway system. Such detour shall temporarily be considered part of the state highway system. The department may create a new temporary road or may use an existing road, highway, or street for a detour.