I believe the single most effective mechanism in the world for promoting widespread transmission of a viral or bacterial pathogen is the New York City subway system. You can introduce a virus anywhere in the world, and within one week I guarantee you it will be all over the NYC subway.
Why is the New York COVID-19 curve youre showing there so steep? Because the NYC subway system is still operating EVEN RIGHT NOW.
This whole thing is a fiasco. Let these urban dumps that function like open sewers lock themselves down and use the military to prevent anyone from escaping. The rest of us have no reason to abide by these stupid restrictions.
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.