Assessment and Management of Air Pollutant Emissions from Vehicles in the Bangkok Metropolitan Region

Abstract

Air pollution has emerged as a critical issue, especially in urban areas, with vehicle emissions being a major contributor to the problem. To effectively address this pressing concern, accurate estimation of current and future traffic emissions is of utmost importance. This study focuses on investigating the emission status and predicting future trends of various vehicles in the Bangkok Metropolitan Region (BMR). To conduct the study, comprehensive statistical analysis was performed to assess the technical characteristics, activity patterns, and operating conditions of different vehicle types, including passenger vehicles, light-duty trucks, heavy-duty buses, heavyduty trucks, and motorcycles. The Computer Programme to Calculate Emissions from Road Transport (COPERT) model was utilized to calculate the emissions of CO, NOx, PM_2.5, VOCs, and CO₂ from these vehicle types in the BMR for the period spanning 2021 to 2050. The COPERT model employs emission factors and adjusts them based on actual operating conditions using correction coefficients. Three distinct scenarios were developed to gauge the potential outcomes. The first scenario, Business as Usual (BAU), represents the continuation of current practices. The second scenario, emission reduction standards (ERS), implements measures to reduce emissions. Finally, the third scenario combines emission reduction standards with the widespread adoption of electric vehicles (ERS and REV). The number of vehicles in each scenario was predicted using the gray model and combined with calibrated emission factors to forecast emissions under different scenarios. The results of the study demonstrate the significance of emission reduction strategies. By implementing ERS alone, the study indicates potential reductions of approximately 0.68% in CO emissions, 2.27% in NOx emissions, 6.71% in PM_2.5 emissions, 2.36% in VOCs, and 0.04% in CO₂ emissions by 2050, compared to the BAU scenario. Even more promising results were observed with the ERS and REV scenario. In this case, the study suggests substantial decreases, including approximately 91.05% in CO emissions, 72.81% in NOx emissions, 78.74% in PM_2.5 emissions, 88.25% in VOCs, and 79.38% in CO₂ emissions compared to the BAU scenario. These findings highlight the potential of emission reduction strategies and the adoption of electric vehicles in significantly improving air quality and reducing pollution levels in the BMR. As such, the study provides valuable insights for policymakers and stakeholders, offering guidance to develop effective measures for sustainable transportation and environmental protection in the region.