The county road administration board shall prepare and distribute to all counties with approved county ferry capital improvement projects, voucher forms for use in requesting annual payments for each approved county ferry capital improvement project.

The county road administration board shall approve such vouchers for payment to the county submitting the voucher. County ferry capital improvement fund warrants shall be transmitted directly to each county submitting a voucher. In the event that project funds remain unspent after the final project payment has been made, the unspent balance will be returned to the county-wide fuel tax account for distribution in accordance with RCW 46.68.120.