; (2) by redesignating paragraphs (2) through (5) as paragraphs (3) through (6) respectively; (3) by inserting after paragraph (1) the following: (2) Additional limitation (A) In general A State, political subdivision of a State, or political authority of 2 or more States may not enact or enforce a law, regulation, or other provision having the force and effect of law prohibiting employees whose hours of service are subject to regulation by the Secretary under section 31502 from working to the full extent permitted or at such times as permitted under such section, or imposing any additional obligations on motor carriers if such employees work to the full extent or at such times as permitted under such section, including any related activities regulated under part 395 of title 49, Code of Federal Regulations. (B) Statutory construction Nothing in this paragraph may be construed to limit the provisions of paragraph (1). ; (4) in paragraph (3) (as redesignated) by striking Paragraph (1)— and inserting Paragraphs (1) and (2)—