The assessment of environmental impact on NO$_2$ (or TSP) emitted by vehicles is important for local residents from the point of view of their health and environmental protection. In the course of field investigations, correct concentrations are measured and meteorological data are observed for numerical simulation. To determine background concentration for numerical simulation, annual average concentrations of NO$_2$ (or TSP) are estimated using the Puff-Plume model. If the estimated result affects the environment, it must be considered in the environmental conservation activity. To make the process of a estimation of environmental assessment more easily, this system is developed. Moreover, this system was supplied a Graphic User Interface (GH) for the user who calculated the concentration of air pollution exhausted from the traffic on general roads except special roads such as interchanges and entrances to tunnels. This system can offer not only the numerical result but also a graphic display. Even a beginner who is not a professional programmer can calculate the result easily.