Since 1990's the air pollution caused by vehicles has become a social problem and the pollutants caused by emission from vehicles in large cities including Seoul metropolitan area exceeded 80% of total pollutants. Particularly, in case of specific constructions such as tunnels, the pollutants emitted in the tunnels are emitted through tunnel portals and the level and range of their impact may be considerably larger than that of common roads. However preceding domestic studies on tunnels were made focused on the quality of air in tunnels, and the studies focused on the impact of pollutants emitted from tunnel portals on near area and the countermeasure for reduction of the impact were very poor. Thus this study was made to suggest the most useful method through consideration of the standard of emitted pollutant calculation, the method to estimate the impact, and their control facilities.
The emission factor used in calculation of emitted quantity of pollutants emitted by vehicles was the one reported in 1990's which was targeted 1980's vehicles on the roads, and it has been pointed out as one of the most important cause of over-estimation. This study intended to suggest an emission factor that may be used most reasonably through comparative analysis of the emission factors of vehicles reported in 1990's, the emission factors of vehicles reported in the U.S.A., Japan, and Europe, and permitted emission standard of new vehicles produced. As a result of this study, the emission factors or foreign countries were found to be difficult to substitute 1990's emission factor becau