; or (B) decreases the efficiency of the National Airspace System, including lowering airport capacity, increasing travel times, or increasing fuel burn; (3) the advisability of using jet aircraft approach or takeoff speeds as a noise mitigation technique; and (4) if the Administrator determines that using jet aircraft approach or takeoff speeds as a noise mitigation technique is advisable, whether any of the metropolitan areas specifically identified in section 157(b)(2) would benefit from such a noise mitigation technique without a significant impact to aviation safety or the efficiency of the National Airspace System. (c) Report Not later than 2 years after the date of enactment of this Act, the Administrator shall submit to the Committee on Transportation and Infrastructure of the House of Representatives and the Committee on Commerce, Science, and Transportation of the Senate a report on the results of the study initiated under subsection (a). 168. Judicial review for proposed alternative environmental review and approval procedures Section 330(e) of title 23, United States Code, is amended— (1) in paragraph (2)(A) by striking 2 years and inserting 150 days as set forth in section 139(l)