High Stopping frequency of heavy vehicles such as refuse trucks produces a large amount of energy which is generated by driving engine during vehicle acceleration. Most of this energy is wasted in form of heat to the environment when the vehicle brakes. This wasted energy normally lost during braking is significant especially in repeated stopping vehicles. This research presents a concept for the hydraulic hybrid system design using automation studio software to build the suggested hydraulic circuit. The classical mechanical traction in traditional vehicle can be replaced by this system without lowering vehicle performance and other satisfaction criteria in addition to achieving the main target from hybridization; regenerate energy which is always lost during vehicle braking and reuse to accelerate it again. It also includes the hydro- mechanical system architecture (which is called SHHS) and its component specification after changes in traditional vehicle structure. The switching matrix for control unit also illustrated. In this paper, the dynamics model for the SHHS (Series hydraulic hybrid vehicle) is constructed by MATLAB/SIMULINK package. The vehicle performance is investigated during various modes of operation at different condition.