(a) General rule.--No person or persons shall occupy a house trailer, mobile home or boat on a trailer while it is being moved upon a highway. (b) Towing prohibited.--No person shall tow on a highway a house trailer, mobile home or boat on a trailer occupied by a passenger or passengers. (c) Exception for certain semitrailers.--A semitrailer which is attached to a truck in an articulating manner by means of a fifth wheel semitrailer coupling device attached to the carrying compartment of the truck may be occupied by a passenger or passengers. The coupling device shall have a two-inch or larger kingpin. All windows shall have safety glass. Some means of electrical or electronic communications approved by the department is required between the cab of the truck and the semitrailer.
Pennsylvania Legal Code