Effective bridge management can be achieved by grasping salt damage locally and taking a maintenance strategy according to the corrosive environment classification of the area. The purpose of this study is to understand the corrosive environment by region, and to clarify the corrosion rate by region by exposure tests using monitoring steel plates. Then, by regression analysis of the corrosion and their causes, we clarify the tendency of the corrosive environment and the amount of adhering salt, and propose a method for estimating the corrosive environment based on the river distance.
