(a) Stations
If final regulations have not been issued pursuant to section 12164 of this title, for new construction or alterations for which a valid and appropriate State or local building permit is obtained prior to the issuance of final regulations under such section, and for which the construction or alteration authorized by such permit begins within one year of the receipt of such permit and is completed under the terms of such permit, compliance with the Uniform Federal Accessibility Standards in effect at the time the building permit is issued shall suffice to satisfy the requirement that stations be readily accessible to and usable by persons with disabilities as required under section 12162(e) of this title, except that, if such final regulations have not been issued one year after the Architectural and Transportation Barriers Compliance Board has issued the supplemental minimum guidelines required under section 12204(a) of this title, compliance with such supplemental minimum guidelines shall be necessary to satisfy the requirement that stations be readily accessible to and usable by persons with disabilities prior to issuance of the final regulations.

(b) Rail passenger cars
If final regulations have not been issued pursuant to section 12164 of this title, a person shall be considered to have complied with the requirements of section 12162(a) through (d) of this title that a rail passenger car be readily accessible to and usable by individuals with disabilities, if the design for such car complies with the laws and regulations (including the Minimum Guidelines and Requirements for Accessible Design and such supplemental minimum guidelines as are issued under section 12204(a) of this title) governing accessibility of such cars, to the extent that such laws and regulations are not inconsistent with this subpart and are in effect at the time such design is substantially completed.