It is expected that autonomous vehicles will become commonplace because of the convenience they provide to drivers. However, this enhanced convenience may increase vehicle driving demand. Therefore, using a household survey conducted in Japan, this paper examines the effects of automated driving on vehicle miles traveled. In the analysis, we assume that automated driving halves both the number of traffic accident risks and driving fatigue incidents. The estimation results show that a household's annual vehicle miles traveled, on average, increase by about 630km to 3,237km due to the introduction of automated driving. If all vehicles in Japan were to be replaced with autonomous vehicles, the annual increase in vehicle driving demand would raise greenhouse gas emissions by 6.5 million to 33.8 million t-CO2. Therefore, authorities need to pay attention to the relation between autonomous vehicles and climate change when promoting and distributing autonomous vehicles.