Before any plat is approved affecting any land within 300 feet of the centerline of a proposed new highway or a highway for which changes are proposed as described in the certification to local officials by the Director of Transportation of any land 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 of Transportation. The Commission shall not approve the plat for 120 days from the date the notice is received by the Director. If the Director notifies the Commission that he shall proceed to acquire the land needed, then the Commission shall refuse to approve the plat. If the Director notifies the Commission 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, the Commission shall, if the plat is in conformance with all provisions of these Regulations, approve the plat.