The county constructing each RAP project may submit vouchers monthly as the work progresses and shall submit a final voucher after completion of each RAP project for the payment of the RATA share of the project cost. Each voucher shall include total project costs to date, including costs covered by other funding sources. The county shall include with each voucher sufficient documentation to verify costs. Reimbursable costs include all eligible direct costs for the design phase, right-of-way phase in allowed regions, and construction phase. Indirect costs shall not be included. The chair of the county road administration board or his/her designee shall approve such vouchers for payment to the county submitting the voucher.