COVID-19 and public transport: Results of early studies on infection risks

By Patrick Troy / Updated: 07 Sep 2020

The COVID-19 pandemic has led to lower occupancy levels and mandatory health inspections across public transport. However, public transport is still a vital part of society. It is an accessible, affordable and sustainable mobility choice. Regaining passengers’ trust is critical and even with actions to reduce the risks across society, it can be hard to dissociate the idea of ‘high infection risk’ from public transport.

A study conducted on high-speed trains in China suggested that there was a transmission risk amongst passengers. The risk depended on the seat location (the closer passengers sit together the greater the risk) and co-travel time (the longer the time spent together the greater the risk). It is worth noting that this study was conducted during the Lunar New Year before the existence of preventative measures.

However epidemiological studies carried out since in Austria, France and Japan have shown quite different results. They analysed clusters of COVID-19 cases and found no clusters connected to public transport. A number of factors could explain this:

  • These studies took place after preventative measures had been put in place, so commuters were more likely to be wearing masks, maintaining safe distances and regularly disinfecting their hands;
  • COVID seems to be transferrable not just by sneezing and coughing, but also by talking and singing, which is less likely to happen between passengers on public transport unless they know each other;
  • Most public transport is at least partially ventilated;
  • Passengers tend to stay on public transport for a short amount of time for daily journeys, so their exposure time is fairly short.

These factors suggest that public transport Is potentially safer than other enclosed spaces, such as gyms and bars. However, pinpointing a cluster of cases to public transport is complicated and the results could simply reflect the difficulty of identifying three or more simultaneous cases in the same vehicle within hours.

Even though COVID-19 is the fastest studied pandemic in human history there are still a lot of unknowns. What we do know is that strict measures can make a difference: wearing face masks, physical distancing, good ventilation, limited conversation and short exposure time all minimise the risk of infection.

Original article first published 17 August 2020 by Sandra Lima

Photo Credit: © Drazen Zigic / - no permission to re-use image(s) without separate licence from Shutterstock.