This study evaluates the impacts of air pollution on trip decision-making and the determinants associated with perceived health risk from air pollution, socioeconomic status, and trip routine. To analyze its impacts based on a comprehensive mechanism, we developed a conceptual framework for trip decision-making process via perceived health risk from air pollution through an extensive literature review. We conducted a survey about trip plan changes due to poor air quality in South Korea, and used an integrated choice and latent variable model to verify the hypotheses in the framework. The result reveals that high perceived health risk encourages people to seek related information, which induces more trip plan changes under poor air quality. People with greater perceived risk tend to make more drastic trip-related decisions by changing or even canceling trip schedules. Moreover, higher-income groups generally perceive greater health risks and eventually seek relevant information more. The findings imply that the gap caused by socioeconomic status brings more frequent exposure of socially disadvantaged groups to polluted air, which can connect to environmental justice problems in society. This study provides noteworthy knowledge of the relationship between air quality and travel behavior to make healthy cities for everyone through environmental justice in transportation.