67 Pa. Code § 601.108
Each trailer in a tandem trailer combination shall, at a minimum, be equipped with the electrical devices and reflectors required by 49 CFR Part 393, Subpart B (relating to lighting devices, reflectors, and electrical equipment).
The provisions of this § 601.108 adopted October 29, 1992, effective October 30, 1992, 22 Pa.B. 5321.