Community noise has been great concerned in public. The traffic noise in seoul, especially has been growing awareness for the quiet living environment. In this paper, the effect on the noise barrier in order to reduce highway noise near on the street has been examined. First barriers have been evaluated at 5 locations in the city. The evaluation is performed before and after construction, with the reference point which does not affected on road traffic volume. Then, noise reducers mounted on the harriers also have been examined. the result shows that it reduces noise level by $3{sim}3.5dB(A)$ with a standard deviation of 2.8 dB(A).