Abstract
Recently, due to the rapid increase in motorization and insufficient supply of transport infrastructure, deterioration of the environment can be observed not only at the city level but also at the global level. This study aims at examining alternatives “modal shift” policies which should be taken to tackle such problems. The introduction of fuel/carbon tax and the improvement of railway are treated. To handle the required analysis, several models are developed. Through the analysis, it is proved that such policies can be efficient and can results in a reduction in the exhausts of carbon.