(a) A business, to the extent that such business contributes to the cost of design, labor, and materials that is for the rehabilitation and improvement of the Harmon Industrial Park roadway, as identified and approved by GEDA, shall be entitled to credit of unpledged business privilege taxes. The basis for contribution to the project shall be the actual cost of the contribution plus the cost of transportation from the point of origin to its destination.

(b) Any unused credits not used in the current tax period may be carried over into subsequent tax periods until such credits are exhausted.

(c) The total credits allowed under this Act shall not exceed the actual dollar amount of the expenditures on the project.