Abstract: A power distribution unit useful in a truck tractor to apply electrical power to a selected one or more of a plurality of signal terminals of a tractor-mounted connector in a tractor-to-trailer electrical connection. The power distribution unit comprises a power bus adapted for connection to a power source, an output terminal corresponding to each signal terminal of the connector, a switch connected between each output terminal and the power bus, and an actuator associated with each switch and operable upon receipt of a respective control signal to operate the associated switch.

Abstract: Correct removal of cargo units 14 from the cargo space 10 of a cargo delivery vehicle uses RFID tags 15 on the cargo units. A RFID transceiver 18 is in the cargo space. A sensor 16 responds to closure of a door to the cargo space to initiate operation of the transceiver to interrogate the RFID tags and to create an inventory of the cargo units then in the space.