Energy requirement of vehicles could be said the second large energy consumption aside from industry. An extremely large percentage (ca. 85%) consumed energy by vehicles is converted to waste heat, i.e. invalid work. To improve working efficiency of vehicles and to retrieve waste energy from vehicles are two essential energy topics in the 21st century. This work presents a mechanical system which will be built in the decelerating downhill roadways to capture the waste energy of vehicles and is internationally patented by the Taiwanese Yeu-Chun green energy technology incorporated company. This developed system is mainly composed of the piston plates and the instantaneous electric generating apparatus in connection with the potential energy storage. In process, the piston plates are built in the decelerating downhill roadways and pressed by the decelerating vehicles for waste energy capturing. The captured energy is either first saved into the potential energy storage for energy collection and then discharged to drive the electric generators or directly applied to the electric generation. The hydraulic drive technique is applied in this system for force transfer from vehicles to the electric generators while vehicles are running over the piston plates. Dimension of the piston plate is L x W = 106 x 56 cm(2) and its piston diameter is 3 cm with piston stroke 3 cm. The results show that the first product generation yielded total working efficiency over 40%. (C) 2011 Elsevier Ltd. All rights reserved.