No commissioner shall receive a salary. Each commissioner shall receive the sum of twenty-five dollars ($25) per day for each day spent in actual attendance on, or in traveling to and from, meetings of the commission or on special assignment for the commission, together with actual expenses incurred in carrying out the provisions of this chapter. Traveling expenses shall be reimbursed at the rate allowed to state employees per mile traveled by automobile or actual fare when traveling by airplane, railway or other manner of transportation.