Nothing in this subchapter shall be construed to affect the authority of the Secretary of Transportation that may exist prior to , 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 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.