Role of income on travel behavior in polluted air

Abstract

Introduction: Polluted air causes health problems and disrupts people's daily lives. Under polluted air conditions, people's travel behavior tends to change, and this can be different by their economic status. In this context, this study explored how travel behavior (i.e., whether to make a trip and what transportation mode to take) changes during times of poor air quality and how the changes vary according to income level. Methods: We conjoined and analyzed the data from a national household travel survey and from air quality measurements collected in South Korea's capital region. Multilevel logistic regression modeling was used to consider the structure of the conjoined data. Results: The modeling results show that people generally responded to polluted air by reducing their trips and by avoiding walking outside or riding bikes. Higher-income groups made fewer trips during weekends and used motorized transportation modes more than those in lower-income groups. However, people with lower incomes also sensitively responded to poor air quality by changing their transportation mode to a more protective one, notably from non-motorized modes to public transit. Conclusions: The results demonstrate social disparity regarding travel-related options in polluted air and emphasize the importance of public transit for lower-income communities to minimize their exposure to polluted air. This study contributes to the existing literature by providing contextualized insight into the role of income on trip generation and mode choice when air quality worsens. The findings from this study can assist in making policies that better protect the whole of society from the growing number of days with polluted air. © 2023 Elsevier Ltd