Wisconsin Statutes Transportation (Ch. 189 to 195) § 195.044. Witness fees and mileage

(1) Each witness who appears before the office or its agent, by its order, shall receive for attendance the fees and mileage now provided for witnesses in civil cases in courts of record, which shall be audited and paid by the state in the same manner as other expenses are audited and paid, upon the presentation of proper vouchers sworn to by such witnesses and approved by the office. Said fees and mileage shall be charged to the appropriation for the office.

(2) No witness subpoenaed at the instance of parties other than the office is entitled to compensation from the state for attendance or travel unless the office certifies that the witness' testimony was material to the matter investigated.