75 Pa. C.S. § 8303
In the case of any person who is subject to Federal regulations pertaining to the transportation of hazardous materials, the department's regulations shall, and in any other case may, as far as practicable, correspond with such Federal regulations. It is the purpose of this section to avoid, as far as practicable, the imposition of conflicting regulations upon persons who operate vehicles subject to Federal regulations, pertaining to the transportation of hazardous materials. It is also the purpose of this section to empower, but not require, the department to prescribe, for persons not subject to the Federal regulations, regulations identical with or similar to those Federal regulations pertaining to the transportation of hazardous materials.
75 Pa.C.S. § 8303