(a) Before assuming the duties of an ex officio road commissioner, a county commissioner must execute a bond in the amount of $3,000 payable to the county judge for the use and benefit of the county road and bridge fund. The bond must be conditioned that the member will:
(1) perform the duties required of the ex officio road commissioner by law or by the commissioners court; and
(2) account for the money or other property belonging to the county that comes into the commissioner's possession.
(b) To be effective, the bond must be approved by the county judge.