; and (ii) to make such improvements as may be necessary for that highway segment to conform with standards applicable to the Interstate System. (B) Authorization of appropriations There is authorized to be appropriated out of the Highway Trust Fund (other than the Mass Transit Account) such sums as may be necessary to carry out this paragraph. (c) Vehicle weight limitations on Interstate System Section 127 of title 23, United States Code, is amended by adding at the end the following: (u) Vehicles on highway segment in Pennsylvania (1) In general If a vehicle could operate legally on the highway segment described in paragraph (2) on the day before the segment was designated as part of the Interstate System, the vehicle may continue to operate on that segment without regard to any requirement under this section. (2) Description The highway segment described in this paragraph is the portion of Interstate Route 99 in Pennsylvania between Interstate Route 180 and the New York border, formerly known as United States Route 15. .