Subsequent to the adoption of the official thoroughfare plan and the passage of this chapter, the plan commission may do the following:

    A.    Determine lines for new, extended, widened or narrowed thoroughfares in any portion of the city and the jurisdictional area thereof;

    B.    Certify to the common council the amended or additional plan under the same procedures as established for the certification and approval of the official thoroughfare plan. (Prior code § 27-29)