The state highways and transportation commission is hereby authorized to take and accept conveyance of title to and ownership of any such bridge, or part thereof, situated within the state of Missouri, subject to any incumbrance against any such bridge and pledge of its tolls previously executed, but not in assumption of any such incumbrance or part thereof existing upon or against any such bridge at the time of such conveyance. And such acceptance of title to and ownership of the same shall not in any manner create any liability, present or future, upon or against the state of Missouri or the state highways and transportation commission thereof, for the payment or assumption of any such incumbrance or any part thereof.