A sheet-like printing medium with easy-separating means which enables one to easily separate the printing medium into separate portions. A drive shaft is positioned along the elongated body, the drive shaft having an input and an output. The processor is further configured to subtract a first fluid density value from the quasi fluid density value for calculating a density correction factor. The first layer 1 has a number of raised portions which are located among the joints 3. These data are sent to the vehicles by optical beacons 5, and presented pictorially on an on-board display in the vehicles. The data output port of the mixing unit is directly or indirectly connected to the data input port of the conversion unit.