In acting upon prior authorization requests for nonemergency medical transportation services, the department shall consider all relevant information in its possession regarding the beneficiary for whom services are requested. The department shall act upon such requests in a timely and expeditious manner. The department shall not form separate units within its field offices to receive and act upon prior authorization requests for nonemergency medical transportation. The provisions of this section shall be applicable only in counties having a population in excess of 6,000,000.