In this study, the environmental impacts of autonomous vehicle were examined through the investigation of the concept, related technologies, development stages, and future prospect of autonomous driving. Based on the investigation, related policy direction and necessary follow-up studies were proposed. According to the result of this study, positive environmental effects can be achieved by increased fuel efficiency and reduced emissions of air pollutants through the autonomous driving technologies and derived effects such as eco-driving, platooning, reduction of road congestion, reduced demand for excessive engine performance, light-sizing and -weighting due to reduced accidents and vehicle sharing. At the same time, however, negative environmental effects can also occur by increase of traveling distance due to decrease of travel cost, new travel demand stratum, increase of traveling speed on highway, and heavier vehicle weight with additional functions, etc. As such, autonomous driving do not necessarily mean environmental benefits. It is necessary to develop a policy that maximizes the environmentally friendly aspects and minimizes the return horns. It is expected that the results of this study will be utilized in the future policy setting related to autonomous driving.