A facility, structure, establishment, business, or location, designed, planned, used or operated for the storage, fueling, servicing, repairing, cleaning and maintenance of motor vehicles designed for carrying freight or merchandise including "commercial motor vehicles," "tractors," "trailers," "truck tractors," as defined in the Vehicle Code of the Commonwealth of Pennsylvania, Act of June 17, 1976, P.L. 162, No. 81, as amended, 75 Pa.C.S.A. § 101 et seq., except the same shall not include the storage, fueling, servicing, repairing, cleaning and maintenance of school busses under contract with or owned by any school district, private school or parochial school in the Commonwealth of Pennsylvania and used for the transportation of school children. The term "truck terminal" shall not include a motor vehicle service facility commonly known as a service station or gas station having a building or service station of not more than 5,000 square feet, excluding canopies, dispensing or selling gasoline or diesel fuel from not more than four islands consisting of not more than three dual pumps per each island, and having on-site storage facilities for gasoline of not more than 40,000 gallons and of diesel fuel of not more than 20,000 gallons.