In Korea, traffic flow, which is prescribed under Traffic Impact Assessment Act is analyzed by traffic volume, V/C, mean speed on the road and LOS(Level of Service) in the intersection. This index does not consider stochastic characteristics of traffic flow. Moreover it is hard to analyze traffic flow well in an entire traffic network because only individual roads and intersections are assayed. This study has been devised to show current traffic flow visually within traffic influence area, and then MOE, according to improvement is studied by applying microscopic-simulation based on car-following theory. To execute this study, previous traffic impact study is replenished, and the change of current traffic flow around the development area is analyzed by using micro simulation program, Vissim. Various outputs from Vissim can be used to convert into monetary.