(a) A planning commission may be created at any time by the act of the legislative body of a municipality.

(b) In any urban municipality, the legislative body may create a planning department headed by a planning director as a substitute for a planning commission, and, in that event all of the powers and duties of planning commissions set forth herein shall be exercised by such planning director, subject to such regulations as that executive body shall from time to time specify, and sections 4322 and 4323 of this title shall not apply to such director. In such event, that legislative body may further create an advisory planning council, which shall only function in an advisory capacity to the planning director in the exercise of his or her powers and duties, and shall have such other functions as that legislative body shall, by resolution, assign to such council. (Added 1967, No. 334 (Adj. Sess.), § 1, eff. March 23, 1968.)