The members of any existing planning commission or body having similar powers and functions established under former laws shall continue in office until the end of their term as so established. New members shall be appointed and vacancies filled only under this chapter. Such commissions shall have, on March 23, 1968, all of the powers and duties of a planning commission created under this chapter. (Added 1967, No. 334 (Adj. Sess.), § 1, eff. March 23, 1968.)