Evaluation of the impact of COVID-19 on transport sustainability

The COVID-19 outbreak changed travel behavior in many ways. This paper evaluates these changes in Tehran, Iran from a transportation sustainability perspective. It uses data from travel surveys before and during the pandemic to evaluate changes in travel activity and their impacts on public transportation (PT) system costs and revenues, air quality, and traffic crashes. A structural equation model (SEM) is used to assess the potential impact of passengers’ characteristics, details of each transportation mode and the severity of COVID-19 on travel behavior. Hypothesis testing is used to compare the changes that occurred in air quality and traffic crashes. SEM outputs indicate that the frequency of trips previously made by sustainable modes and changes in regular trips have the highest impact on the sustainability of trips made during the COVID-19 pandemic. Air quality declined in many city districts. The pandemic caused reductions in PT ridership and increase in private cars use, which threaten the long-term sustainability of public transit services. Crash fatalities declined slightly, especially during periods of movement restrictions. However, the motorcycle fatal crashes increased in comparison to the reduction in its trips, apparently due to increased traffic speeds. The government did not use the pandemic as an opportunity to promote sustainable and low-contagion modes. This analysis suggests that the COVID-19 outbreak reduced overall transportation sustainability in Tehran.