Abstract: A vehicle video recording device includes surveillance cameras, an electronic memory for temporarily storing the videos shot by the cameras, a hard disk drive (HDD) for receiving and storing the video data from the electronic memory, a running environmental data memory for storing the running environmental data along a route, on which the vehicle runs, which data affects the recording performance of the HDD, and a recording controller for controlling transmission and recording of the video from the electronic memory to the HDD during a route section, where the recording performance of the HDD does not lower, based on the running environmental data. This structure allows saving the recording device from having sensors, and yet, the video recording device can positively records the video shot by the cameras even if vibration or impact happens.

Abstract: The present invention includes an electric wire laid in cars, a PLC modem connected with each electric wire and a terminal connected with each PLC modem. The terminal can communicate through the electric wire by using the PLC modem. When the cars are coupled with each other, the electric wires are electrically connected with each other and a new address is allocated to a control unit which has a unique address provided for each terminal.