As the human material life style growth and the industrialization have been taking place, the overland transporting system also has been growing with its size, mass, and velocity. Especially, sice domestic overland transporting system is rapidly growing, the smooth function of highway is very important in economic and military matters. To meet these requirements, the bridge's usage, safety, and durability have to be revaluated very carefully. But by focusing only on the quantity of the public basic facility has brought many tragedies to us. To prevent such incidents, there are many steps we can take such as careful planning, careful designing, careful constructing, using good materials, and steady maintenance; the most important thing is the maintenance. Taking all this in consideration, in this thesis I'd like to construct a system ralated to the safety of ferroconcrete bridge according to fuzzyidea, and at the same time creating a scientific maintenance system would be very important to gain credibility from regular citizens.