Spatial Analysis of Multi-Pollutant Road-Transport Emission Hotspots for Sustainable Transportation Management in Bangkok: The Bangkok Air Pollution Emission Intelligence System (BAPEIS)

Abstract

Air pollution is a major environmental health challenge in rapidly urbanizing Southeast Asian cities, where road transport emissions occur close to population-sensitive land uses. This study develops the Bangkok Air Pollution Emission Intelligence System (BAPEIS), a GIS-based framework for quantifying and visualizing multi-pollutant road transport emissions across Bangkok to identify emission hotspots and support transportation emission management. BAPEIS integrates road network, traffic activity, vehicle fleet, emission factors, population, and air quality data within a 10 × 10 km analytical grid (A1–H8), estimating PM2.5, CO, NOx, SOx, and total hydrocarbon (THC) emissions from vehicle kilometers traveled and pollutant-specific emission factors, using the 2023–2024 Bangkok Metropolitan Administration (BMA) traffic count and the Department of Land Transport (DLT) vehicle fleet data with EMEP/EEA emission factors. Results identify a common central Bangkok multi-pollutant hotspot core that remained spatially stable between years even as the single leading grid shifted from E6 (2023) to F6 (2024). Citywide SOx emissions declined by 83.7% between 2023 and 2024, substantially more than the 13–22% decline for the other four pollutants, coincident with Thailand’s 2024 Euro5 fuel standard transition; these are raw inventory differences, not statistically tested estimates. BAPEIS provides a transparent, city-scale framework linking emission inventory science with environmental health planning, demonstrating the value of pollutant-specific spatial intelligence for targeted transportation emission management.