“Cities with the highest use of public transportation did not have the highest rates of deaths; if anything just the opposite,” William A. Petri Jr., a professor of internal medicine and associate director of microbiology at the University of Virginia Medical School, said via email. “The authors are careful to point out the limitations of the analysis, but it really argues against conventional wisdom, and suggests that with proper safeguards of masking and social distancing that public transportation could be used safely.”