Nothing in this subchapter shall be construed to affect the authority of the Secretary of Transportation that may exist prior to August 8, 2005 , with respect to— (1) research into, and regulation of, hydrogen -powered vehicles fuel systems integrity, standards, and safety under subtitle VI of title 49; (2) regulation of hazardous materials transportation under chapter 51 of title 49; (3) regulation of pipeline safety under chapter 601 of title 49; (4) encouragement and promotion of research, development, and deployment activities relating to advanced vehicle technologies under section 5506 [1] of title 49; (5) regulation of motor vehicle safety under chapter 301 of title 49; (6) automobile fuel economy under chapter 329 of title 49; or (7) representation of the interests of the United States with respect to the activities and programs under the authority of title 49. ( Pub. L. 109–58, title VIII, § 821 , formerly § 816, Aug. 8, 2005 , 119 Stat. 855 ; renumbered § 821, Pub. L. 117–58, div. D, title III, § 40314(1) , Nov. 15, 2021 , 135 Stat. 1008 .) [1] See References in Text note below. Editorial Notes References in Text Section 5506 of title 49 , referred to in par. (4), was repealed by Pub. L. 112–141, div. E, title II, § 52010(a) , July 6, 2012 , 126 Stat. 887 .