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.