Before any zoning amendment is approved affecting any land within 300 feet of the centerline of a proposed new highway or highway for which changes are proposed as described in the certification to local officials by the Director of Transportation, or within a radius of 500 feet from the point of intersection of the centerline with any public road or highway, the Planning Commission shall give notice, by registered or certified mail, to the Director. The Commission may proceed as required by law, however, Council shall not approve the amendment for 120 days from the date the notice is received by the Director. If the Director notifies the City that he shall proceed to acquire the land needed, then the City shall refuse to approve the rezoning. If the Director notifies the City that acquisition at this time is not in the public interest or upon the expiration of the 120-day period or any extension thereof agreed upon by the Director and the property owner, Council shall proceed as required by law.