All county roads designated in accordance with sections 39-2001 and 39-2002 shall be maintained at the expense of the county; Provided, that in counties under township organization not operating under the county road unit system, the county board may, by resolution entered on its records, delegate to the township board the duty of maintaining in the township any road which has been designated after September 7, 1947, as a county primary road.
Neb. Rev. Stat. §§ 39-2003