There shall be a state interagency motor pool within the Department of Administrative Services. Said motor pool shall provide motor vehicles to state agencies on a rental basis. Proceeds from rentals of such motor vehicles by said motor pool shall be deposited in the purchasing revolving fund maintained by said department and all direct expenses incurred by said motor pool shall be charged against said fund on order of the State Comptroller. The Commissioner of Administrative Services shall adopt rules regarding the rental and use of motor vehicles provided by the motor pool.