An aluminum alloy forged material for automotive vehicles comprises 0. A plurality of motion sensors for detecting speed of traffic information are placed along one or more roadways. A Signature selecting unit selects one of the corresponding Signatures at random from the Signature table storage unit, on the basis of the magnitude of the transmission loss level outputted from a transmission loss level deciding unit. The method further includes rotating the shaft and waking the processor for a period of time and drawing energy to the processor from the energy storage device to provide the processor in an active mode during the period of time.