(a) Procedure. The procedure prescribed by law in civil and criminal cases concerning the attendance and testimony of witnesses, the administration of oaths and affirmations, and proceedings to enforce the remedies and protect the rights of the parties shall govern traffic cases as far as they are applicable unless provided otherwise by these rules or by the law. Payment of witness fees and costs of serving witnesses in civil traffic cases shall be made in the same manner as in a criminal traffic case.(b) Use of Affidavits. A defendant in a civil infraction case may offer evidence of other witnesses through use of one or more affidavits. The affidavits shall be considered by the court only as to the facts therein that are based on the personal knowledge and observation of the affiant as to relevant material facts. However, the affidavits shall not be admissible for the purpose of establishing character or reputation.