Except as otherwise provided in this act, on August 15, 1975, officers and employees who were engaged immediately prior to said date in the performance of powers, duties and functions of any state agency which becomes a part of the department of transportation or the powers, duties and functions of which are transferred to the secretary of transportation, and who, in the opinion of the secretary of transportation, are necessary to perform the powers, duties and functions of the department of transportation, shall become officers and employees of the department of transportation. Any such officer or employee shall retain all retirement benefits and all rights of civil service which had accrued to or vested in such officer or employee prior to August 15, 1975. The service of each such officer and employee so transferred shall be deemed to have been continuous. All transfers and any abolishment of personnel in the classified service under the Kansas civil service act shall be in accordance with civil service laws and any rules or regulations adopted thereunder.