(a) The term "junk" means old or scrap copper, brass, rope, rags, batteries, paper, trash, rubber debris, waste, junked, dismantled, or wrecked automobiles, trucks and other motor vehicles, or parts of them, iron, steel, and other old or scrap ferrous or nonferrous material.

(b) The term "automobile graveyard" shall mean any establishment which is maintained or used for storing, buying, or selling wrecked, scrapped, ruined, or dismantled motor vehicles or motor vehicle parts.

(c) The term "junkyard" shall mean an establishment which is maintained or used for storing, buying, or selling junk, or an automobile graveyard, and the term shall include garbage dumps, sanitary fills and scrap processors.

(d) The term "scrap processor" shall mean any person, firm or corporation engaged only in the business of buying scrap iron and metals, including, but not limited to, old automobiles, for the specific purpose of processing into raw material for remelting purposes only, and whose principal product is ferrous and nonferrous scrap for shipment to steel mills, foundries, smelters and refineries, and maintaining an established place of business in this State and having facilities and machinery designed for such processing.

(e) "Interstate system" means that portion of the National System of Interstate and Defense Highways located within this State, as officially designated, or as may hereafter be so designated, by the Department of Transportation, and approved by the Secretary of Commerce or other appropriate federal official, pursuant to the provisions of Title 23 of the United States Code.

(f) "Federal aid primary system" means that portion of connected main highways, as officially designated, or as may hereafter be so designated, by the Department of Transportation, and approved by the Secretary of Commerce or other appropriate federal official, pursuant to the provisions of Title 23 of the United States Code.

(g) "Department" means the Department of Transportation.