I once rode into Manhattan under the Hudson and then around Manhattan on subways. Packed like sardines standing up, bumping into dozens, breathing all their exhaled air.
Never again. I don’t think you could devise a better CV spreading machine. (CV lasts for days on surfaces, and up to 3 hours floating in the air in closed spaces.
High-rise elevators are also up there as optimal spreading chambers.
Have you ever tried to ride from Penn station to Queens at 5pm...only Tokyo would rival the amount of human packing. I was literally spooning the poor woman in front of me and had nuts to butts just like the Army with the guy behind me, no one even blinked about the close contact every one just packs in personal space ha forget about it. In the summer there’s no ac in the stations I was in NYC for 2 weeks in Jan , 2 weeks in Jul and again for 2 weeks in November. July was miserable in the subways. Winter is warm ish but by no means warm. They will have a million cases by the time they finally shut down the system.