Before any fragment, section, or route on the state highway system shall be abandoned, the department shall place upon public record in the department a written instrument describing the proposed abandonment. Such written instrument shall bear the department seal and shall be dated and subscribed by the Director-State Engineer and state upon what conditions, if any, the abandonment shall be qualified and particularly whether or not the title or right-of-way to any abandoned fragment or section shall be sold, revert to private ownership, or remain in the public. Such written instrument shall be certified by the department and be recorded in the office of the register of deeds of each county wherein any portion of the state highway system is being abandoned. No fee shall be charged for such recording. On such recording, the abandonment is complete.