Select the check mark button on a Transport to mark it as full. It will be removed from the list of available transports.
It is important to use this button to remove older or unused transports so that the transport list stays short. Having too many older or no longer needed transports will slow down loading the list.
Note that these transports will still stay in the transports list on the Transports screen. Transports need to be archived to be removed from the Transports screen.