(a) (1) The total of expenditures from the State Public Transportation Fund under paragraphs (4), (5), and (6) of Code Section 32-5-21 plus expenditures of federal funds appropriated to the department shall be budgeted by the department over two successive budgeting periods every decade. However, such budgeting shall not include:

(A) Any federal funds specifically designated for projects that have been earmarked by a member of Congress in excess of appropriated funds;

(B) Any funds for a project undertaken for purposes of providing for the planning, surveying, constructing, paving, and improving of The Dwight D. Eisenhower System of Interstate and Defense Highways within the state; or

(C) Any funds for a project undertaken for purposes of providing for the planning, surveying, constructing, paving, and improving of any part of the state designated freight corridor, when such designation is made by the director of planning with approval from a majority of the board.

(2) The first budgeting period shall commence immediately following redistricting of congressional districts and shall be for a duration of five years. The second budgeting period shall continue until the beginning of the budgeting period following the next redistricting of congressional districts after each decennial census; provided, however, that if the congressional districts have been redrawn prior to a new decennial census, but after the approval of an existing map based on the last decennial census, the budgeting period shall include two successive budgeting periods. The first budgeting period shall end upon approval of the new redistricting and the second budgeting period shall commence from the date such redrawn congressional districts have been approved and shall continue until the next budgeting period following the next redistricting of congressional districts. The department shall budget such expenditures such that at the end of such budgeting period funding obligations equivalent to at least 80 percent of such total for such budgeting period shall have been divided equally among the congressional districts in this state, as those districts existed at the commencement of such budgeting period, for public road and other public transportation purposes in such districts.

(b)

(1) The board may upon approval by two-thirds of its membership authorize a reduction in the share of funds allocated pursuant to this Code section to any such congressional district if such supermajority of the board determines that such district does not have sufficient projects available for expenditure of funds within that district to avoid lapsing of appropriated funds.

(2) In the event that funding becomes available to the department which could not otherwise be allocated among congressional districts due to the allocation requirements of this Code section, the board may upon approval by a majority of its membership authorize a waiver of such allocation requirements to the extent necessary to allow the expenditure of such funding, and any project, projects, or portion thereof undertaken with such additional funding shall be in addition to those projects funded in accordance with the allocation requirements of this Code section in the fiscal year in which the additional funds became available or any subsequent year; provided, however, that any such waiver shall be valid only for the fiscal year in which it is granted, and any funds budgeted pursuant to a waiver granted by this paragraph which were not obligated by the end of such fiscal year shall not be obligated in violation of the allocation requirements of this Code section in a subsequent fiscal year unless a majority of the board again authorizes a waiver of the allocation requirements in such subsequent fiscal year.

(c) Provisions of this Code section may be waived pursuant to subsection (b) of Code Section 32-5-1 only upon approval by two-thirds of the membership of the board.