; and (B) may not enforce any date-specific deadlines or requirements that are inconsistent with the requirement under subsection (a). (2) Rule of construction Except as required under paragraph (1), nothing in this section may be construed to require the Secretary to issue regulations to implement this section. (c) Amending the phase-out date If the Secretary, based on the data contained in the report issued pursuant to subsection (d), determines that the phase-out date under subsection (a) cannot be met due to insufficient manufacturing capacity or would otherwise result in significant impacts to interstate commerce, the Secretary shall delay the phase-out scheduled under subsection (a) to December 31, 2028. (d) GAO review Not later than 18 months after the date of the enactment of this Act, the Comptroller General of the United States shall issue a report to the Secretary, the Committee on Commerce, Science, and Transportation of the Senate and the Committee on Transportation and Infrastructure of the House of Representatives that— (1) identifies the manufacturing capacity of tank car manufacturers in North America, that manufacture tank cars to meet DOT–117 and DOT–117P specification requirements; (2) identifies the retrofit capacity of tank car manufacturers and other entities in North America that can retrofit DOT–111 tank cars to meet DOT–117R specification requirements; (3) estimates the schedule of replacing tank cars currently in service that are reaching the end of their life cycle; (4) identifies the number of tank cars that need to be phased out or retrofitted under subsection (a) and paragraph (2) and the number that could be retrofitted