- (a) The State Highway Commission will serve formal complaints.
- (b) It will also serve supplemental, amended, and cross complaints when it has granted leave to file such pleadings.
- (c) If no agent has been designated, service may be made by posting in the office of the secretary of the commission.
- (d) If the complaint involves only the lawfulness of rates, fares, charges, classifications, or practices, service may be made upon an attorney in fact of a carrier or freight forwarder who has filed a tariff or schedule on behalf of such carrier or freight forwarder.