Optimization Models for Developing Air Quality Maps for Road Networks Using Public Transportation

Air pollution is a significant environmental problem with detrimental impacts on human health and society. At present, air quality monitoring is only undertaken at stationary sites within a given region, although air concentrations differ between specific locations and surrounding environmental factors, even within the same region. Thus, a comprehensive monitoring system covering extensive regions and implementing stepwise air quality monitoring at varying heights in residential areas is required for accurate air quality measurement. This research proposes a road network air quality map that utilises public bus transportation for detailed unit air quality measurements. The optimisation problem of bus route decision-making for efficient measurement operations is addressed in this study. The objective of this study is to meet the air quality measurement requirements for each road section while minimizing the number of bus routes required. An integer programming model is proposed to address this problem. The proposed model is then applied to a case study conducted in the downtown area of Gangnam-gu, Seoul to validate the feasibility of utilizing public transportation for air quality measurements. The case study findings show variations in the number of bus routes due to changes in air quality measurements. Furthermore, the integration of public transportation into the proposed air quality monitoring system reveals possibilities for improving the overall air quality measurement system.