How long it took transit ridership to recover from disruptive events: A review into the recent history

The COVID-19 pandemic has caused an unprecedented decrease in transit ridership around the world. Some major cities in the United States have lost over 80% of their transit riders, and some transit agencies have been forced to reduce service and work with a skeleton crew at times. Although the future of the COVID-19 pandemic and its long-term effect on transit systems are still unclear, much can be learned from previous disruptive events, such as terrorist attacks and epidemics, in the past 30 years, so as to draw qualitative and quantitative insights about the public reactions, ridership recovery periods, and transit agency responses during and after those events. The goal is to facilitate the understanding of the current COVID-19 pandemic and inform future decisions of transit agencies. This paper provides a historic review of the impacts of terrorist attacks such as the London and Madrid bombing, the Tokyo sarin gas, and the 9/11 attacks; and past epidemics and pandemics, such as Severe Acute Respiratory Syndrome (SARS), H1N1 swine flu, Middle East Respiratory Syndrome (MERS), and Ebola. It was found that most of these reviewed incidents (except for the 9/11 attacks) did not impose prolonged post-event effects on transit ridership for more than one year. In addition, executive orders (e.g., school closures), transportation service levels (e.g., screening time for air travel and rail station closures), public fear, media reports, and reduced tourists were frequently mentioned as key factors that impacted transit ridership. The review also identified measures that could potentially help restore transit ridership, such as sanitizing vehicles and facilities, adjusting services, and launching promotions and advertisements. Finally, insights on the ongoing COVID-19 pandemic are drawn through comparisons with historical events.