Abstract
In this paper, we studied the effects of compact city policy on infrastructure maintenance cost such as water supply and sewage systems. Defining compact city policy as the policy which increases population density, we estimated how much reduction in infrastructure maintenance cost would be expected if such policy was adopted. According to our study, the policy would save about 71 billion yen annually in 2030. However, we also noted that the number of the people who will be exposed to the risk of earthquake attack might increase if compact city policy is adopted without paying attention to it.
