Spatio-temporal patterns of air quality on commuter lane of the sub-urban area of Yogyakarta, Indonesia

Yogyakarta, a city based on culture, education, and tourism, has different commuting activities from other industrialized cities in Indonesia. On the other hand, the city is also dominated by motorcycles, like most cities in Indonesia and Southeast Asia. The movement of commuters by motorcycle affects the instantaneous air quality. In this paper, the results of an investigation of the spatio-temporal pattern of air quality of commuter routes in the suburbs of Yogyakarta are presented. Data were collected through observation by measuring five air quality parameters and vehicle intensity in 10 commuter routes in Yogyakarta. Data were analyzed using GIS analysis using average nearest neighbour, statistical analysis using simple linear regression, and matching analysis referring to The World Air Quality Index and Vianney and Erfianto (2023), supported by descriptive analysis. There are three critical findings from this study. First, air quality varies spatially and temporally, with differences among commuter routes and travel times. Second, the relationship between passing vehicle intensity and air quality is unique. Some positively correlate with linear, exponential, logarithmic, or polynomial relationship properties. Third, poor air quality tends to be found on main routes with high vehicle intensity. In summary, this study provides new insights into air quality patterns concerning commuter traffic in motorcycle-dominated cities in Indonesia.