Recent advances towards steer-by-wire technology have promised significant improvements in vehicle handling performance and safety. This technology inspired from aeronautics, consists in replacing the traditional mechanical linkages and/or hydraulic power assist with electrical equivalents. This paper describes the adopted approach for development of a new dynamic model of a Steer-by-wire system with hydraulic assistance in the case of stopped vehicle. The aim is to establish dynamic equations of the forces and torques exchanged between handwheel and the front wheels during steering operations. Some simulation results are provided. The proposed model will be experimented using a prototype equipped with handwheel feedback system.