(a) The term rest area, when used in this Part, shall mean any area provided by the State Department of Transportation along State highways, maintained by the State and designated as “ rest area” by signs caused to be erected within the State highway right-of-way by the Commissioner of Transportation.

(b) The term parking area, when used in this Part, shall mean any area provided by the State Department of Transportation along State highways, maintained by the State and designated as “ parking area” by signs caused to be erected within the State highway right-of-way by the Commissioner of Transportation.

(c) The term scenic overlook, when used in this Part, shall mean any area provided by the State Department of Transportation along State highways, maintained by the State and designated as “scenic overlook” by signs caused to be erected within the State highway right-of-way by the Commissioner of Transportation.

(d) The term vehicle, when used in this Part, shall mean every device in, upon or by which any person or property is or may be transported or drawn upon a highway, except devices moved by human power.

(e) The term commercial activity, when used in this Part, shall include the exhibiting of goods or samples of goods for sale and the taking of orders therefor, the exchange of commercial paper, the buying and selling of goods and services, the transfer of commercial cargoes or portion of cargoes from one vehicle to another, the advertising of goods and services, the solicitation of riders, the solicitation from or selling to an occupant of any vehicle, or any other activity in furtherance of a transaction of commerce, trade or mercantile pursuits.