In addition to the provisions of Section 12.08.140, amendments may be initiated as follows:

    A.    The common council may direct the plan commission to prepare an amendment, as desired, and submit it to public hearing within sixty days after formal written request by the common council.

    B.    The owners of fifty percent or more of the area of property abutting upon a street may also petition the plan commission requesting an amendment to the official thoroughfare plan. (Prior code § 27-30)