The members of the authority shall be compensated by a per diem as is authorized by Section 25-3-69 for each day spent in actual discharge of their duties, and shall be reimbursed for mileage and actual expenses incurred in the performance of their duties as provided in Section 25-3-41. No authority member may incur per diem, travel, or other expenses unless previously authorized by vote at a meeting of the authority, which action shall be recorded in the official minutes of said meeting.