(a) Any road district tax that was authorized by the electors at an annual or special town meeting during the years 1975 through 1979 for a period not exceeding 5 years, but that was not re-authorized within 5 years after it was authorized due to Public Acts 81-779, 81-821, and 81-1509, which repealed the 5-year limitation, is hereby validated for all tax levy years subsequent to 1980 only to the extent that the authority to tax did not automatically expire after 1980.
     (b) Any road district tax that was levied prior to 1980 shall not be subject to the requirements of subsection (b) of § 30-20 of the Township Code if that tax was or is:
         (i) re-authorized by the electors at an annual or