(1) The department shall maintain all public highways or portions of public highways that it maintained on July 1, 1976.
(2) The department shall assume the maintenance responsibilities for paved secondary roads as roads are identified cooperatively by the department and the county or counties in which a paved secondary road or paved secondary road segment is located. The department may phase in maintaining the paved secondary roads but must have completely assumed the responsibilities by January 1, 2001.