Wisconsin Statutes Vehicles (Ch. 340 to 351) § 344.17. Requirements as to form and amount of security

(1) The security required under s. 344.14 shall be in such form and in such amount as the secretary may require but in no case in excess of the limits specified in s. 344.15(1) with reference to the acceptable limits of a policy or bond. The person depositing security shall specify in writing the person or persons on whose behalf the deposit is made and, at any time while such deposit is in the custody of the secretary, the person depositing it may, in writing, amend the specification of the persons on whose behalf the deposit is made to include an additional person or persons, subject to the limitation that a single deposit of security shall be applicable only on behalf of persons required to furnish security because of the same accident.

(2) The secretary may reduce the amount of security ordered in any case if, in the secretary's judgment, from evidence submitted, the amount ordered is excessive or has become excessive by filed release on part of the liability or by adjudication reducing the extent of the liability. In case the security originally ordered had been deposited at the time the reduced amount is ordered, the excess over the reduced amount shall be returned to the depositor or the personal representative forthwith, notwithstanding s. 344.20.