Fluvial flood and pluvial flood will increase due to climate change caused by global warming, and so it is necessary to take preventive measures in Japan. The authors have previously developed a risk assessment system for urban inundation countermeasures. However, this system has a problem in evaluating the vulnerability of road traffic obstacles, which is improved. As a result of applying this system, there is almost no difference in the risk assessment results between the current scenario and the 2-degree scenario. On the other hand, there is a difference in the results of risk assessment between the current scenario and the 4-degree scenario, and it is clarified that the risk increases in the case of the 4-degree scenario. It is shown that the improved system can also be applied to the planning of urban inundation countermeasures in consideration of climate change.