Investigating factors affecting university students' use of subway before and after COVID-19 outbreak: A case study in Tehran.

Identifying and examining factors affecting the use of the subway is critical for developing countries as they struggle with high levels of auto use and resulting congestion, noise and air pollution. In this research, we surveyed students of a top-ranked university in the capital of Iran before and after the COVID-19 outbreak to identify the factors affecting their use of the subway. Chi-square tests show that gender, level of education, and being the only child of the family have the highest impact on using a private car. These variables had no significant influence on students' mode choice to university before the COVID-19 pandemic, when students' mode choice was only a function of their residence location. However, the pandemic has affected priorities for mode choice. For instance, hygiene and social distancing, which were previously insignificant to students, are now among their top criteria, and travel time and cost are less important for students than in the past. As a result, subway use has significantly decreased. Based on the results of the research, when making relevant policies, more attention should be paid to the groups of women, undergraduate students and single children that are more likely to use private cars.