Section 4. No license shall be granted for the establishment, maintenance, use or operation of a junkyard or automotive dismantler and recycler within one thousand feet of the nearest edge of the right-of-way of any highway except the following:
(a) Junkyards and automotive dismantlers and recyclers which are lawfully in existence prior to January 1, 1967.
(b) Junkyards and automotive dismantlers and recyclers which, because of screening by natural objects, plantings, fences, or other means found appropriate by the secretary, are not visible from the main-traveled way of the highway.
(c) Junkyards and automotive dismantlers and recyclers located within areas zoned for industrial use under authority of law.
(d) Junkyards and automotive dismantlers and recyclers located within unzoned areas which the secretary shall find are used for industrial activities.
(4 amended July 13, 1977, P.L.77, No.28)