The Effects of Bus Rapid Transit Line on Air Pollutant Emissions Case study of BRT Tehran, line4 (Chamran highway

Air pollution is among the most concerning challenges in metropolises. A significant part of this pollution is in regard to transportation. Some transportation projects, like highway construction or street widening projects would encourage the citizens to use their private cars instead of public transportation which will lead to more emissions of contaminants. In most cases, estimation of transportation projects by cost-benefit analyzing will lead to an underestimation of destroying effects. The transportation fleet is the major source of pollutants in cities. Bus Rapid Transit (BRT) lines which are considered as an index of sustainable transportation, has been built in Tehran metropolitan areas recently. In this study, the evaluation of transportation projects with respect to sustainable transportation criteria in urban areas has been taken into account and also environmental effects of transportation projects have been measured. This paper reviews Tehran BRT Line 4 in order to evaluate the effect of exclusive lane of BRT on Chamran highway’s amount of air pollutants. For this purpose the amount of emitted pollutants in BRT line 4, are compared based on the traffic volume information. This modeling includes two scenarios: before and after the construction of BRT Lines. Comparison of modeling results would clarify the effect of BRT lines on reduction of the amount of air pollutants.