(a) In General.—If monies are deposited into the Highway Account or Mass Transit Account pursuant to a law enacted subsequent to the date of enactment of the FAST Act, the Secretary shall make available additional amounts of contract authority under subsections (b) and (c).

(b) Amount of Adjustment.—If monies are deposited into the Highway Account or the Mass Transit Account as described in subsection (a), on October 1 of the fiscal year following the deposit of such monies, the Secretary shall—

(1) make available for programs authorized from such account for such fiscal year a total amount equal to—

(A) the amount otherwise authorized to be appropriated for such programs for such fiscal year; plus

(B) an amount equal to such monies deposited into such account during the previous fiscal year as described in subsection (a); and

(2) distribute the additional amount under paragraph (1)(B) to each of such programs in accordance with subsection (c).

(c) Distribution of Adjustment Among Programs.—

(1) In general.—In making an adjustment for programs authorized to be appropriated from the Highway Account or the Mass Transit Account for a fiscal year under subsection (b), the Secretary shall—

(A) determine the ratio that—

(i) the amount authorized to be appropriated for a program from the account for the fiscal year; bears to

(ii) the total amount authorized to be appropriated for such fiscal year for all programs under such account;

(B) multiply the ratio determined under subparagraph (A) by the amount of the adjustment determined under subsection (b)(1)(B); and

(C) adjust the amount that the Secretary would otherwise have allocated for the program for such fiscal year by the amount calculated under subparagraph (B).

(2) Formula programs.—For a program for which funds are distributed by formula, the Secretary shall add the adjustment to the amount authorized for the program but for this section and make available the adjusted program amount for such program in accordance with such formula.

(3) Availability for obligation.—Adjusted amounts under this subsection shall be available for obligation and administered in the same manner as other amounts made available for the program for which the amount is adjusted.

(d) Exclusion of Emergency Relief Program and Covered Administrative Expenses.—The Secretary shall exclude the emergency relief program under section 125 and covered administrative expenses from an adjustment of funding under subsection (c)(1).

(e) Authorization of Appropriations.—There is authorized to be appropriated from the appropriate account or accounts of the Highway Trust Fund an amount equal to the amount of an adjustment for a fiscal year under subsection (b) for any of fiscal years 2017 through 2020.

(f) Revision to Obligation Limitations.—

(1) In general.—If the Secretary makes an adjustment under subsection (b) for a fiscal year to an amount subject to a limitation on obligations imposed by section 1102 or 3018 of the FAST Act—

(A) such limitation on obligations for such fiscal year shall be revised by an amount equal to such adjustment; and

(B) the Secretary shall distribute such limitation on obligations, as revised under subparagraph (A), in accordance with such sections.

(2) Exclusion of covered administrative expenses.—The Secretary shall exclude covered administrative expenses from—

(A) any calculation relating to a revision of a limitation on obligations under paragraph (1)(A); and

(B) any distribution of a revised limitation on obligations under paragraph (1)(B).

(g) Definitions.—In this section, the following definitions apply:

(1) Covered administrative expenses.—The term "covered administrative expenses" means the administrative expenses of—

(A) the Federal Highway Administration, as authorized under section 104(a);

(B) the National Highway Traffic Safety Administration, as authorized under section 4001(a)(6) of the FAST Act; and

(C) the Federal Motor Carrier Safety Administration, as authorized under section 31110 of title 49.

(2) Highway account.—The term "Highway Account" means the portion of the Highway Trust Fund that is not the Mass Transit Account.

(3) Mass transit account.—The term "Mass Transit Account" means the Mass Transit Account of the Highway Trust Fund established under section 9503(e)(1) of the Internal Revenue Code of 1986.