- (a) Every pleading, protest, intervention, or verified statement filed by any party and tendered to the State Highway Commission for filing shall include a certificate of the party or his or her attorney showing simultaneous service thereof upon all parties to the proceeding made by registered or certified mail with return receipt required.
- (b) The return receipt or a photocopy thereof shall be filed with the commission.
- (c) Applications, formal complaints, supplemental complaints, amended complaints, cross complaints, and letters to the commission relating to oral arguments and subpoenas, when service is required, may be served by depositing same in the United States Postal Service with sufficient postage attached thereto to ensure delivery and a certification of such service signed by the applicant or his or her attorney.