The commission, the officials thereof, and all state officials may do such acts and make such agreements not inconsistent with law as are necessary or desirable in connection with the duties and powers conferred upon them respectively by law regarding the construction, maintenance, operation, and insurance of toll bridges or other highway crossings, and the transportation facilities thereof or thereto, or the safeguarding of the funds and revenues required for such purposes and the payment of the indebtedness incurred therefor.