Japan is dominated by public transit and is one of the countries least affected by it. Transit is not unsafe when people follow distancing procedures and wear masks / don't talk loudly. This was backed up by research

"It’s a similar situation in Japan, where researchers failed to connect a single cluster to the country’s commuter trains, said Hitoshi Oshitani, a virologist and public health expert at Tohoku University. The vast majority of the clusters were instead traced to gyms, bars, live music venues, karaoke rooms and similar establishments where people come in close contact with one another,"

https://www.scientificamerican.com/article/there-is-little-e...

The only indoor environment comes close to an average BART commute as far as human density is the center of the dance floor in a nightclub at capacity. Japan is famously even worse. How is that not close contact?

People in train don't talk.

https://www.worldometers.info/coronavirus/country/france/ shows about 8000 cases per day in France (pop: 65M) I can't find a breakdown by region but the news reports say that there's a lot of cases caused by vacationers, presumably in the south.

https://www1.nyc.gov/site/doh/covid/covid-19-data-recent.pag... says that NYC (pop: 8.5M) is averaging about 1650 cases per week. https://new.mta.info/coronavirus/ridership says there were 1.5M subway passengers on 9/3.

Riding transit doesn't seem like the issue. Not wearing masks and respecting social distancing seem more likely problems.

As usual, Taipei is a counterexample.

Air pollution has been recognized as a contributing factor to respiratory illnesses, COVID-19 among them. More use of public transportation instead of driving has actually been advocated as a public-health goal in some regions. The idea is that as long as masks are used on public transportation, the societal benefits of less driving outweigh the individual risks of COVID-19 transmission.