75 Pa.C.S. § 3809: Restriction on alcoholic beverages.

(a) General rule.--Except as set forth in subsection (b), an individual who is an operator or an occupant in a motor vehicle may not be in possession of an open alcoholic beverage container or consume a controlled substance as defined in the act of April 14, 1972 (P.L.233, No.64), known as The Controlled Substance, Drug, Device and Cosmetic Act, or an alcoholic beverage in a motor vehicle while the motor vehicle is located on a highway in this Commonwealth.

(b) Exception.--This section does not prohibit possession or consumption by any of the following:

(1) A passenger in the passenger area of a motor vehicle designed, maintained or used primarily for the lawful transportation of persons for compensation. This paragraph includes buses, taxis and limousines.

(2) An individual in the living quarters of a house coach or house trailer.

(c) Penalty.--An individual who violates this section commits a summary offense.