(a)
(1) The responsibility for authorizing travel, or any expenses in connection therewith, shall be placed upon the board or commission in charge or upon the administrative head of each state agency.
(2) No travel expenses shall be authorized or allowed without the approval of the board, commission, or administrative head of any agency.
(b) It shall be the responsibility of the administrative head of any agency to keep on file in the place of business of the agency, subject to audit, copies of all supporting documents and required receipts for expenses incurred in connection with the travel authorizations and allowances for persons traveling in behalf of the agency.