Vehicular networks have been considered as the key technology of cooperative driving safety applications that can significantly reduce the congestion but it use high number of resources ,in this paper understanding how this parameter vary in research till. environmental impact (e.g., energy consumption and carbon footprint). To increase the efficiency of transportation, it has been suggested to create intelligent transportations systems (ITS) by using advanced and emerging technologies (computers, sensors, wireless communications, etc.) in transportation to save lives, time and energy