A method and apparatus adaptively scales the decoder input for a low-cost user equipment to reduce the memory requirement without degrading decoder performance. A roadway includes a base layer of a compacted in situ material andor a wear layer disposed on the base layer. The accumulated times may be a time that a respective piezoelectric element unit is in a driven state. In one example, the band gap in the base region is smaller than the band gap in the emitter and collector regions. The system further includes an energy-storing device connected with the pullout section and the extendable section.