On January 16 to May 31, 2012, Korea Expressway Corporation was carried out an pilot overweight enforcement using high-speed weigh-in-motion at Gyeongbu expressway 195.0k (Gimcheon) and Jungbunaeryuk expressway 119.5k (Seonsan). In this study, it is attempted to analyze the practical effect of high-speed weigh-in-motion by comparing the average total weight and traffic volume of eight weeks before and after the these overweight enforcement, respectively. The main results are as follows: First, the result of analysis of the change in average total weight and traffic volume, it was found that it did not differ after as in previous traffic volume, and the total weight is reduced. This means that the total weight is not reduced by decreasing freight traffic, but by decreasing the total weight. Therefore, it can be seen that there is an effect of pilot overweight enforcement using high-speed weigh-in-motion. Second, the average total weight and total weekly traffic volume decreased rapidly starting from the start of the overweight enforcement, but there was showing a tendency to increase gradually again.