In this study an algorithm estimating total load and axial load was conducted using BWIM(Bridge Weigh-in-Motion) system with precision analysis model. Driving test for running vehicle is necessary but it needs much cost, time, and especially hard to applicate to various driving condition. Thus we need a numerical-simulation method for resolving the cost and time problems of driving test for vehicle, and a way to measure bridge responses reflecting many unpredictable situations. Using a precision analysis model reflecting the dynamic characteristic contributes to increase the accuracy in numerical simulation. In this paper, we conduct a numerical simulation to apply a precision analysis model, which reflects the dynamic characteristic of a bridge using the Bridge Weigh-in-Motion system, and suggested a method of overloaded vehicle enforcement technology using the precision analysis model.