(a) The allowance in the foundation school program for each county for transportation shall be the sum of the following computations:
(1) A percentage of the transportation costs incurred by the county for maintenance, operation and related costs exclusive of all salaries, including the costs incurred for contracted transportation services and public utility transportation, as follows:
(A) For each high-density county, eighty-seven and one-half percent;
(B) For each medium-density county, ninety percent;
(C) For each low-density county, ninety-two and one-half percent;
(D) For each sparse-density county, ninety-five percent;
(E) For any county for the transportation cost for maintenance, operation and related costs, exclusive of all salaries, for transporting students to and from classes at a multicounty vocational center, the percentage provided in paragraphs (A) through (D) of this subdivision as applicable for the county plus an additional ten percent; and
(F) For any county for that portion of its school bus system that uses as an alternative fuel compressed natural gas or propane, the percentage provided in paragraphs (A) through (D) of this subdivision as applicable for the county plus an additional ten percent: Provided, That for any county receiving an additional ten percent for that portion of their bus system using bio-diesel as an alternative fuel during the school year 2012-2013, bio-diesel shall continue to qualify as an alternative fuel under this paragraph to the extent that the additional percentage applicable to that portion of the bus system using bio-diesel shall be decreased by two and one-half percent per year for four consecutive school years beginning in school year 2014-2015: Provided, however, That any county using an alternative fuel and qualifying for the additional allowance under this subdivision shall submit a plan regarding the intended future use of alternatively fueled school buses;
(2) The total cost, within each county, of insurance premiums on buses, buildings and equipment used in transportation;
(3) An amount equal to eight and one-third percent of the current replacement value of the bus fleet within each county as determined by the state board: Provided, That the amount for the school year beginning July 1, 2015, will be $15,000,000 and the amount for the school year beginning July 1, 2016, will be $18,000,000. The amount shall only be used for the replacement of buses. Buses purchased after July 1, 1999 that are driven one hundred eighty thousand miles, regardless of year model, will be subject to the replacement value of eight and one-third percent as determined by the state board. In addition, in any school year in which its net enrollment increases when compared to the net enrollment the year immediately preceding, a school district may apply to the state superintendent for funding for an additional bus or buses. The state superintendent shall make a decision regarding each application based upon an analysis of the individual school district's net enrollment history and transportation needs: Provided, That the superintendent shall not consider any application which fails to document that the county has applied for federal funding for additional buses. If the state superintendent finds that a need exists, a request for funding shall be included in the budget request submitted by the state board for the upcoming fiscal year; and
(4) Aid in lieu of transportation equal to the state average amount per pupil for each pupil receiving the aid within each county.
(b) The total state share for this purpose is the sum of the county shares: Provided, That no county shall receive an allowance which is greater than one-third above the computed state average allowance per transportation mile multiplied by the total transportation mileage in the county exclusive of the allowance for the purchase of additional buses.
(c) One half of one percent of the transportation allowance distributed to each county shall be for the purpose of trips related to academic classroom curriculum and not related to any extracurricular activity. Any remaining funds credited to a county for the purpose of trips related to academic classroom curriculum during the fiscal year shall be carried over for use in the same manner the next fiscal year and shall be separate and apart from, and in addition to, the appropriation for the next fiscal year. The state board may request a county to document the use of funds for trips related to academic classroom curriculum if the board determines that it is necessary.